Kelly Barnhill, MBA, CN, CCN, discusses nutrition in autism based on recent publications. She outlines research updates on amino acid patterns, probiotics, and dietary interventions, underscoring both what we know and what we don’t know. The speaker discusses the clinical interpretation and application of this research, touching on common nutrient deficiencies before the Q&A.

In this webinar:

0:00 – Introductions
2:00 – Prospective study on amino acid patterns
5:50 – Prospective Study on Probiotic Intervention
7:40 – Systematic Review of Dietary Intervention and Gut Health
10:54 – Bibliometric Analysis of Influential Articles
13:47 – Systematic Review of Probiotics in Autism
16:06 – Nutrition Reviews Study on Mediterranean Diet
19:28 – Study on Gluten- and Casein- Free Diet
21:48 – Review on Ketogenic Diet
26:16 – Food, Nutrition, and Autism
27:57 – Systematic Review – Food as Medicine
34:40 – Clinical interpretation and application
40:30 – Micronutrients
44:10 – Q&A

Prospective Study on Amino Acid Patterns 

Dr. Barnhill outlines a 2025 study on amino acid patterns in over 1,200 children (2-8 years) with autism. Researchers found lower levels of glutamine in children with autism and significant differences in several amino acids across groups (2:00). Specifically, the study noted that those with neurological impairment were deficient in amino acids that presented with susceptibility to neurocytotoxicity and oxidative stress, while those with nutritional concerns presented with a different set of issues, pointing more toward metabolic concerns. Barnhill explains that these findings substantiate clinical observations and suggest that specific amino acid imbalances may be related to different manifestations of autism, supporting the use of nutritional therapeutic intervention to balance amino acid levels. The speaker emphasizes that this is the only amino acid study presented in a prospective way that has been published in a reputable journal in the past few years. 

Amino Acid Patterns in Children with Autistic Spectrum Disorder: A Preliminary Biochemical Evaluation (Ferraro et al., 2025)

Prospective Study on Probiotic Intervention 

The presenter outlines another recent study that speaks to the concerns of effects of probiotic support for children with autism, AD/HD, and children with both diagnoses (AuDHD) (5:50). Children were given a probiotic or a placebo for three months. Researchers saw a significant improvement in hyperactivity and impulsivity in both the autism and ADHD groups. Most notably, the “comfort score” on a quality-of-life instrument showed significant improvement for autistic children. Barnhill notes that, although this is a small study, its findings support clinical observations that probiotics can improve gastrointestinal symptoms and other related issues in children with autism, potentially impacting their quality of life.

Effect of Probiotics on the Symptomatology of Autism Spectrum Disorder and/or Attention Deficit/Hyperactivity Disorder in Children and Adolescents: Pilot Study (Rojo-Marticella et al., 2025)

Systematic Review of Dietary Intervention and Gut Health 

Barnhill examines a systematic narrative review of all articles published between 2000 and 2024 related to autism, dietary interventions, probiotics, and the microbiome. (25-year review) (7:40). The review validated that dietary intervention can improve GI symptoms and gut health for children with autism, which in turn improves their quality of life. Researchers also identified a cycle where sensory processing issues lead to food avoidance (ARFID), which decreases microbiome diversity and increases harmful microbial species, leading to a neuroinflammatory process that affects behavior (9:12). The speaker asserts that this review provides a strong rationale for addressing GI and microbiome concerns as part of a comprehensive care plan for individuals with autism.

Unraveling the Connections: Eating Issues, Microbiome, and Gastrointestinal Symptoms in Autism Spectrum Disorder (Tomaszek et al., 2025)

Bibliometric Analysis of Influential Articles 

The speaker highlights another 25-year study that reviewed all publications on microbiome treatment in autism since 2000 to identify the most impactful and cited articles (10:54). This is one of the first in a series of bibliometric analyses. The study identified two landmark publications: a 2013 mouse model study that established the link between the gut microbiome and ASD, and a very early, relatively small study from 25 years ago that showed improvements in both GI symptoms and behavior in a small group of autistic children treated with an oral antibiotic. These two studies, along with many more, laid the groundwork for the growing field of gut-brain research in autism and further validated the clinical utility of targeting gut health.

Influential articles in autism and gut microbiota: bibliometric profile and research trends (Ying et al., 2025)

Systematic Review of Probiotics in Autism 

Barnhill discusses a systematic review that analyzed 10 completed and published clinical studies, as well as 18 ongoing clinical trials, on the use of probiotics in autism. (13:47). Reviewers found that probiotics can improve social behaviors, drastically improve GI symptoms, and positively alter the gut microbiome when used appropriately. The presenter emphasizes this paper as a valuable and easily accessible resource for clinicians and parents, as it provides research backing for the use of probiotics in addressing a range of symptoms beyond just GI issues – essentially describing what we’ve learned and why it’s important.

Probiotics in autism spectrum disorders: a systematic review of clinical studies and future directions  (Barba-Vila et al., 2025)

Nutrition Reviews Study on Mediterranean Diet

Barnhill notes that we are seeing more and more solid research emerging about how dietary intervention benefits individuals across the board, highlighting that there is no one-size-fits-all approach for any of us and what that means for clinical applications. She outlines a 2025 evaluation of all studies on children (6-16 years) with autism and ADHD, examining responses to nutritional interventions (16:06). The paper concluded that 70% of individuals who followed a Mediterranean diet showed significant improvement in ADHD symptoms. It also noted significant improvements in depression (80%) and anxiety (50%). The speaker states that these results suggest that focusing on a whole, unprocessed Mediterranean-style diet can be a profound and effective intervention for improving neurological and mental health symptoms. 

Mediterranean Diet and Mental Health in Children and Adolescents: A Systematic Review (Camprodon-Boadas et al., 2025)

Study on Gluten- and Casein-Free Diet

The speaker outlines another 2025 study that evaluated a 12-week trial involving 80 children (4-10 years), using a strict, prescribed gluten- and casein-free diet in combination with and separate and distinct from a neurodevelopmental physical therapy program (19:28). Barnhill notes that families prepared meals on their own, meaning there was no technical control group. Researchers saw significant gains in gross motor skills and cognitive function only when the diet was combined with the therapy program. The dietary group alone showed no significant changes. This study suggests that a multidisciplinary, holistic approach is key, and that dietary interventions may be more effective when combined with other therapies.

Effect of Therapeutic Diet Along with Special Physiotherapy Program on Gross Motor Development and Cognitive Function in Autistic Children: A Randomized Controlled Trial (Alsayegh et al., 2025)

Review on Ketogenic Diet

A review of all published papers on the ketogenic diet for individuals with autism found that the diet is not appropriate for everyone due to the high heterogeneity of autism. However, Barnhill continues, it does hold great potential for some individuals by reducing bacterial dysbiosis, decreasing pro-inflammatory cytokines, enhancing gut health, and providing a neuroprotective effect via ketone bodies (21:48). Barnhill underscores that while the ketogenic diet can be effective for the right patient, it should only be implemented with professional guidance due to its complexity and potential dangers when applied inappropriately. More research is needed.

Exploring the potential of the ketogenic diet in autism spectrum disorder: metabolic, genetic, and therapeutic insights (Schrickel et al., 2025)

Food, Nutrition, and Autism

The presenter provides a summary article describing our current understanding of nutrition and autism from a societal and cultural perspective. The paper tangentially addresses all the issues that people in the US should be aware of and attuned to, including environmental and food exposures from prenatal to childhood. Barnhill asserts this study is foundational for building an appropriate dietary approach and understanding what barriers might exist (26:16). 

Food, nutrition, and autism: from soil to fork (Shepard et al., 2024) 

Systematic Review – Food as Medicine

The speaker notes a recent systematic review that addresses the use of dietary intervention and therapeutic nutritional support across various diagnoses (27:57). The authors highlight several publications that support the idea that food can be considered a form of medicine and is increasingly understood as a pharmaceutical component in health and medical diagnoses. Barnhill emphasizes the importance of not viewing food choices and dietary recommendations for autism as “other” to the general population’s nutritional understanding. Culturally, we continue to recognize that our diets are integral to health and need to be taken seriously. She states that “we need to hold autism research and interventions to the same standards.” This study ultimately resolidifies the interconnectedness of the gut and brain by highlighting the impact of microbiome health in the GI system on both the vagal nerve and cognition (31:00). 

Nutraceuticals in Psychiatric Disorders: A Systematic Review (Bozzatello et al., 2024)

Clinical interpretation and application

According to the presented information, Barnhill asserts that clinicians should assume that diet matters and that a nutritionist or dietary specialist should be included in care counseling and planning for children and adults with autism (34:40). She underscores the importance of avoiding packaged food products, ensuring fiber and water intake are sufficient, and addressing feeding concerns with care and compassion. She also suggests incorporating family and community into diet changes, meal preparation, and eating habits. The speaker also suggests working with a professional to outline any specialized diets (37:40). 

Micronutrients & Therapeutic Support

Barnhill lists common micronutrient deficiencies, including B vitamins, fat-soluble A and D, and Omega-3 fatty acids. She notes that addressing gaps with supplemental support is reasonable and appropriate to meet the minimal needs in the case that someone doesn’t have access to those nutrients via diet (40:30). She cautions viewers about the supplement market, noting that it is not regulated; and suggests consulting with someone well-versed in what’s needed and the efficacy of different brands before the Q&A (44:10). 

Mojdeh Mostafavi, MD, describes gastrointestinal conditions commonly seen in individuals with autism, including gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), Eosinophilic GI disease (EGID), avoidant/restrictive food intake disorder (ARFID), disorders of the gut-brain interaction (DGBI), and constipation. She outlines recent research on the prevalence of these conditions in people with autism, emphasizing the complexities of symptom presentation, drivers, and care. The speaker provides a free social story for endoscopies and considers the relationship between pain expression and GI conditions. Mostafavi discusses the difficulties of transitioning from pediatric to adult healthcare in autism. She summarizes the presentation before the Q&A.

Handouts are available HERE

Recommendations for evaluation and treatment of common gastrointestinal problems in children with ASDs – PubMed (article discussed during the talk)
Understanding and Treating Self-Injury Book (book mentioned during the talk)

In this webinar:

1:10 – Introduction, disclosures, language preferences
2:35 – Autism and gastrointestinal conditions
10:20 – Gastroesophageal Reflux Disease (GERD)
14:10 – Inflammatory bowel disease
18:00 – Eosinophilic GI disease (EGID)
22:10 – Avoidant/restrictive food intake disorder (ARFID)
27:15 – Disorders of the gut brain interaction (DGBI)
33:00 – ASD and constipation
37:00 – Resources and tips
46:20 – Conclusion
48:00 – Q&A

Autism and GI conditions

Mostafavi defines autism and lists common co-occurring conditions, including seizures, psychiatric disorders, and gastrointestinal (GI) conditions (2:35). She notes that between ~40% – 70% of children with autism have GI symptoms with a significantly higher lifetime prevalence and that measurement tools don’t capture all GI symptoms (5:30). The most common GI complaints reported by autistic people are constipation, abdominal pain, feeding difficulties, encopresis, and weight loss/failure to thrive (8:40). The speaker underscores the importance of defining these conditions in autism and discusses some of the most common co-occurring GI conditions. 

• The Prevalence of Gastrointestinal Problems in Children Across the United States With Autism Spectrum Disorders From Families With Multiple Affected Members (Wang et al., 2011)
• Gastrointestinal Symptoms in Autism Spectrum Disorder: A Meta-analysis (McElhanon, 2014)
• Gastrointestinal Symptoms in Children with an Autism Spectrum Disorder and Language Regression (Valicenti-McDermott et al., 2008)
• Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study (Mostafavi et al., 2024)

Gastroesophageal Reflux Disease (GERD)

Gastroesophageal Reflux Disease (GERD) occurs when stomach acid refluxes into the esophagus. This is one of the better-understood GI conditions in autism. Mostafavi outlines a recent study that found that people with autism have a higher risk of developing erosive esophagitis and esophageal ulcers compared to non-autistic groups (10:20). She remarks that acid-blocking medications can mitigate some risk and describes the BRAVO wireless and nasal probe tests for GERD (10:20). 

• Evaluation of Gastroesophageal Reflux Disease in Children on the Autism Spectrum: A Study Evaluating the Tolerance and Utility of the BRAVO Wireless pH Monitoring (Rodriguez et al., 2022)

Inflammatory bowel disease

Inflammatory bowel disease (IBD) is broadly characterized by Crohn’s disease and ulcerative colitis, which are caused by inflammation of the GI tract. A recent systematic review and meta-analysis (6 studies, 11 million participants) found an association between autism and the later development of IBD. Mostafavi notes that children with autism often have more potent treatments (second-tier biologics) for GI conditions compared to non-autistic children with GI issues, underscoring their severity in autism (14:10). 

• Association of Autism Spectrum Disorders and Inflammatory Bowel Disease (Lee et al., 2018)

Eosinophilic GI disease (EGID)

Eosinophilic GI disease (EGID) looks at the entire GI tract and is associated with an imbalance in the immune system potentially related to food sensitivities. Over time, complications can include fibrosis and eosinophilic esophagitis (EOE). The speaker outlines a recent systematic review and meta-analysis (6 studies, +700,000 participants), which revealed an association between autism and EGID, where the prevalence of autism in the EGID population is 21.59% (18:00). 

Avoidant/restrictive food intake disorder (ARFID) 

Avoidant/restrictive food intake disorder (ARFID) is related to at least one of the following:

• Fear of consequences (symptoms that the food triggers)
• Sensory aversion
• Lack of interest/awareness of appetite cues 

Unlike other eating disorders, ARFID is not related to body appearance. Mostafavi notes inadequate caloric intake and deficiencies in micronutrients and vitamins as concerns associated with ARFID. Recent research shows a significant relationship between autism and ARFID, and sensory issues are the most commonly described driver (22:10). The presenter suggests trying treatments like oral desensitization and pairing foods and asserts that applying what works in other intervention spheres to ARFID may be possible (25:20). 

• The Co-Occurrence of Autism and Avoidant/Restrictive Food Intake Disorder (ARFID): A Prevalence-Based Meta-Analysis (Sader et al., 2024)
• Avoidant/restrictive food intake disorder and severe food selectivity in children and young people with autism: A scoping review (Bourne et al., 2021)

Disorders of the gut brain interaction (DGBI)

The gut-brain access involves both nervous systems; many neurotransmitters are produced in our guts. Mostagavi asserts that just because labs come back negative does not mean that GI symptoms are not real because there is no specific test for DGBI (27:15). A retrospective study found that nearly one-third of participants seen through an autism-specific clinic experienced functional GI conditions. The speaker underscores how difficult pain localization can be for people with autism due to complications with interoception (31:00). 

• Functional Gastrointestinal Disease in Autism Spectrum Disorder: A Retrospective Descriptive Study in a Clinical Sample (Penzol et al., 2019)
• Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study (Mostafavi et al., 2024)

Autism and constipation

Constipation is one of the most reported GI symptoms associated with autism. However, chronic constipation does not seem to be associated with a higher rate of abnormal colonic motility in autism. Mostafavi outlines research showing that children with autism are more likely to visit the ER and be admitted to the hospital for constipation-related issues compared to children with other or no chronic conditions. This significantly increases healthcare costs and utilization, increasing the chances of poor quality or lack of treatment (33:00). 

• Evaluation of Chronic Constipation in Children With Autism Spectrum Disorder (Coe et al., 2023)

Resources and tips

The presenter notes a 2010 article published in Pediatrics as a good reference for GI issues in autism. The article talks about constipation, guidelines for evaluation in patients with high-risk, mitochondrial conditions, and medication (37:00). Mostafavi suggests using a joint provider who can obtain information on health history, blood and stool work, imaging studies, etc., to compile a complete picture of drivers and symptoms (38:15). Endoscopies can be particularly helpful in assessing GI disturbances in autism and Mostafavi provides a free endoscopy social story available in English, Spanish, Brazilian Portuguese, Arabic, and Haitian Creole (40:00). 

Access Google Drive with social story documents – https://bit.ly/endoscopysocialstory

The speaker highlights that many behavior issues in autism are associated with pain, like irritability, oppositional behavior, meltdowns, and more. She notes the Understanding and Treating Challenging Behaviors in Autism book and how it describes causes of aggression and self-injurious behavior (SIB) in autism as having both physiological and social/behavioral causes. She lists pain behaviors that are often misinterpreted, highlighting that people can demonstrate one or many forms of behavior across different contexts (41:55). Mostafavi touches on the transition from pediatric to adult care and how difficult it can be for autistic people to acquire the necessary care and support (44:00). 

Summary

The speaker summarizes the presentation, highlighting that the majority of people with autism have associated GI-related symptoms or conditions, the most common of which are DCBI, GERD, IBD, EGID, and ARFID. She emphasizes the importance of comprehensive evaluation with guidance from a gastroenterologist where necessary. Mostafavi reminds viewers that children with autism become autistic adults with similar care needs (46:20). She notes the ongoing complexities of discourse around the association between GI issues and autism before the Q&A (48:00). 

Originally published on March 4, 2025.

Dr. Bradley Ferguson, PhD, a 2024 research grant recipient, discusses emerging research on the interaction of GI symptoms and stress in autism. He outlines recent investigations highlighting the connection between GI issues, cortisol levels, and internal and external behaviors. The speaker discusses electrodermal activity (sweat) as a way to measure and predict problem behaviors and considers the potential for treating stress to alleviate GI symptoms. Ferguson underscores the importance of real-world data and outlines ongoing work funded by ARI, which uses smartwatches to monitor physical and social indicators of stress behavior over three weeks. He describes current hypotheses and potential implications for this work before the Q&A.

In this webinar:

1:30 – Stress and the gut
6:30 – Stress and communication
13:13 – Electrodermal activity
17:20 – Treating the stress response
25:30 – Ongoing work
31:47 – “CORE Autism” smartwatch app
37:45 – Implications
39:35 – Summary
42:00 – Q&A

The gut and stress

The prevalence of co-occurring gastrointestinal (GI) issues in autism ranges from 9 to 91%, with constipation being the most common (1:30). Research shows that many autistic people have a heightened stress response which activates the sympathetic nervous system – fight or flight mode – and inhibits stomach function. Ferguson and his team look at GI issues through a stress lens, suggesting that activation of the sympathetic nervous system is related to a lot of GI issues (3:00). He outlines past work that shows a positive relationship between levels of cortisol, a stress marker, and constipation (4:30). Similar work shows that having co-occurring anxiety significantly altered parasympathetic nervous system activity in the lower GI tract, meaning that anxiety is related to GI symptoms in autism (5:40). 

In a 2019 study, Ferguson and colleagues used caregiver questionnaires for 340 autistic children and adolescents to assess correlations between GI conditions and behavior issues (6:30). Results showed that across all ages, 65% experienced constipation, 50% experienced stomach aches, 29% experienced diarrhea, and 23% experienced nausea, where 53% were taking medications for other conditions (ADHD, seizures), and 93% were not taking any GI meds (9:30). In children between the ages of 1 and 5, nausea significantly predicted aggression. Ferguson says that this correlation is likely to do with the children’s inability to communicate their nausea, which leads them to act out. In participants between 6 and 18 years old, anxiety, withdrawn behavior, and somatic complaints were 11% more likely to experience aggression, stomachaches, and nausea, respectively, and less likely to experience certain other GI symptoms (10:55).

The speaker summarizes research findings to date, highlighting that non-verbal young children may use aggression to communicate somatic complaints and that older children have more internalizing behaviors associated with GI symptoms. 

Associations between cytokines, endocrine stress response, and gastrointestinal symptoms in autism spectrum disorder (Ferguson et al., 2016)

Psychophysiological Associations with Gastrointestinal Symptomatology in Autism Spectrum Disorder (Ferguson et al., 2016)

The Relationship Among Gastrointestinal Symptoms, Problem Behaviors, and Internalizing Symptoms in Children and Adolescents With Autism Spectrum Disorder (Ferguson et al., 2019)

Electrodermal activity and problem behavior

Electrodermal activity, or skin sweat, is part of the stress response triggered by the sympathetic nervous system. Using a smartwatch, researchers were able to track skin conductance (sweat) from baseline to post-behavior levels (13:13). Results showed a rise in sweat about 60% of the time prior to a problem behavior occurring and a return to baseline afterward about 45% of the time. The average rise in skin conductance before a behavior was around 10 minutes (15:15). 

Examining the Association Between Electrodermal Activity and Problem Behavior in Severe Autism Spectrum Disorder: A Feasibility Study (Ferguson et al., 2019)

Treating the stress response

Ferguson and his team assessed a trial of propranolol, a beta blocker (blocks stress response), in children and youth with autism. Results showed a significant reduction in anxiety for the propranolol group compared to controls (17:20). He outlines an fMRI study on the relationship between GI issues and amygdalar activity. The study revealed that participants taking propranolol (which crosses the blood-brain barrier) showed a neutral relationship between GI symptoms and amygdala activity. In contrast, those taking nadolol (which does not cross the blood-brain barrier) or a placebo showed a positive correlation. Ferguson explains that these findings indicate that propranolol is blocking the stress response, which may be related to GI issues (19:25). Future research will include transcutaneous vagus nerve stimulation (tVNS) to test the effect of parasympathetic nervous system (rest and digest) activation on GI symptoms (23:45). 

Ongoing work

The research outlined to this point has been strictly lab-based, and the speaker highlights the need for real-world “ecological” monitoring of stress behavior. Lab studies are often stressful in and of themselves, so they may not reflect real-world functioning. Ferguson’s ongoing study, funded by ARI, aims to examine differences in verbal social communication data from 30 autistic people with GI symptoms and 30 without over a three-week period. Data will be collected using smartwatches that track pulse-rate variability, or the time variation between heartbeats, measured with photoplethysmography (PPG). Researchers will also examine differences in autonomic nervous system functioning in relation to GI symptoms (25:30). 

Verbal and social activity will be recorded on a smartwatch app that Ferguson and his team developed called “CORE Autism (31:47).” The app measures the total time spoken by a participant. It has reached 90% agreement between what researchers hear and what the algorithm hears (35:35). The speaker underscores the importance of real-world data and how much we miss with typical laboratory-based questionnaires. Researchers hypothesize that pulse rate variability will be significantly lower for the group with GI issues, indicating a higher stress response. They also hypothesize that there is less social communication among the GI group, possibly due to increased stress (36:48).

Ferguson emphasizes that findings from this study will provide real-world evidence of stress and sociability, allowing a potentially different take on the connection between GI issues and stress for autistic people. For example, if stress is heightened in the GI group, implications for treatment could be huge. The presenter notes that more research could be done to address what happens to GI symptoms when stress is addressed and vice versa (37:45). This study will be finished in 2026. 

Summary

Ferguson reviews the presentation, highlighting that GI symptoms like constipation are prevalent in autism and often associated with stress response and internalizing behaviors, which may differ by age. The stress response may also precede problem behaviors in autism, providing treatment options based on stress reduction via pharmacological, vagal, and behavioral avenues. While preliminary data are exciting, more research is needed in these areas (39:35). Ferguson provides thanks and acknowledgments before the Q&A, where he discusses enteroception, SSRIs, nutrition, smartwatch usage, and more (42:00). 

Originally published November 19, 2024

This is a joint presentation by ARI and the World Autism Organisation.

Professor Carmelo Rizzo, MD, discusses adverse reactions to food and the critical role of intestinal microbiota in autism. He outlines the history of clinical nutrition and highlights the role of chronic inflammation in disease pathology. The presenter considers the interplay of inflammation, altered gut absorption, and food intolerances, underscoring the high occurrence of GI issues in autism and their correlation to behavioral characteristics. Rizzo discusses implications for clinical practice before the Q&A. 

This is a joint presentation by ARI and the World Autism Organisation.

Handouts are available HERE

In this webinar: 

0:00 – WOA & ARI introduction
6:10 – Speaker background and introduction
9:30 – Total load effect
12:30 – Clinical nutrition
15:44 – Food adverse reactions & inflammation
19:45 – Stress response theory
23:00 – Food intolerance vs. food allergy
24:50 – Altered gut absorption
29:00 – Food intolerances
31:30 – The gut microbiome
34:50 – Microbiota and autism
40:28 – Clinical implications
41:45 – Q&A

Introduction

Rizzo explains the total load effect as the idea that our overall health depends on numerous factors, including genetics, emotional and physical environments, inhalants, electromagnetic fields, and nutrition, to name a few (9:30). He highlights nutrition as a critical aspect of prevention and care for many conditions, citing research on the connection between food allergies, behavior, and diet from the early 20th century. Basic principles of clinical nutrition emphasize removing the toxin or chemical and repairing any chronic damage/inflammation, particularly to sensitive organs (12:30). The presenter notes pioneering researchers in ecology and how their work has impacted how contemporary researchers and practitioners understand complex neurological conditions (13:25). 

• Neuropathic manifestations in infants and children as a result of anaphylactic reaction to foods contained in their dietary (Shannon, 1922)
• Elimination Diets and Patient’s Allergies. A Handbook of Allergy (Rowe, 1944)

Food adverse reactions & inflammation

Food adverse reactions include allergies, pseudoallergies, hypersensitivity, toxic reactions, and food intolerances, all of which can lead to inflammation  (15:44). Rizzo describes how inflammation keeps us alive by destroying bacteria and viruses but how it can cause intense injury to organs and tissues if not addressed. Inflammation occurs differently in each person and can manifest in multiple ways simultaneously. Common external presentations of inflammation include osteoarthritis, sore throat, eczema, rhinitis, migraines, and multiple sclerosis (17:30). The presenter notes the connection between inflammation and depression, cancer, obesity, Alzheimer’s, and heart disease, underscoring the importance of correctly identifying and addressing chronic inflammation (18:40). 

Rizzo defines stress as a non-specific response of the body to harmful stimuli (19:45). To illustrate immune system function under the stress theory, he uses the analogy of a barrel holding water (functioning). At first, it holds well based on its build (genetics) and age, but the barrel can only hold a certain amount of water (adapt to a certain point). If the water flow (environmental stressor) doesn’t stop, water begins to spill out of the barrel (physical manifestation/symptom). Those with a full barrel develop food or chemical imbalances that present as conditions or symptoms (20:40). The speaker describes complementary science, underscoring the ability to identify what substances should be added or removed from the body based on specific indications (22:00). 

Altered gut absorption

The speaker highlights the importance of intestinal microbiota in the creation and absorption of crucial vitamins and nutrients, noting the specific balances required for proper immune function (24:50). He details the layers of the intestinal barrier and underscores the role of the mucosal immune system within the gut (26:25). Alterations to the intestinal barrier cause gut permeability, allowing macromolecules into the body where they may be recognized as foreign and activate the body’s defense mechanism. Anything from genetics to emotional stress can cause changes in the gut microbiome (27:45).

Food intolerances

Food intolerances are characterized by an inability to absorb or metabolize certain nutrients, causing an abnormal reaction to specific foods (23:00). Rizzo provides examples of biological food families and highlights their importance in addressing food intolerances. If ingestion of foods within the same family continues, he explains, the body won’t properly detox, and intolerance will persist (29:00). Food intolerances can manifest in any organ, and the reaction window is 72 hours, so what feels like a direct reaction to one food could be a buildup of inflammation in the body (30:10). Symptoms related to food intolerances occur in the central nervous system (headache, depression), genital-urinary systems (vaginal irritation, cyclic cysts), respiratory systems (nasal congestion, rhinitis), skeletal muscle (muscular cramps, articular cogency), gastrointestinal tract (nausea, IBS, Crohn’s disease), and skin (eczema, rash, facial paleness) (31:15).

The gut microbiome

The intestinal microbiota is composed of billions of cells and is one of the largest, most complex bacterial ecosystems on the planet (31:30). Rizzo discusses the development paths and general functions of the gut microbiota for infants, children, adults, and the elderly (32:30). The microbiome’s metabolic functions, such as vitamin production and amino acid synthesis, make it a critical factor in disease prevention and care (34:00).

Microbiota and autism

Individuals with autism have unique intestinal bacterial populations correlated with various autism traits. The presenter outlines a 2005 study on autism-related behaviors and GI experiences with more than 900 participants (34:50). The most common GI disturbances reported were constipation (48%), diarrhea (28%), abdominal pain (55%), and gastroesophageal reflux (10%), with an inflammatory index of 40% (37:20). Histological (tissue and cell structure) findings showed esophagitis, chronic gastritis, colitis, and eosinophilic gastritis (38:08). Participants were prescribed pharmacological and dietary interventions. 

At a twelve-month follow-up, 150 participants reported improvements in GI pain (64%), bowel complaints (84%), reflux (41%), muscle mass (40%), hyperactivity/aggression (65%), attention (34%), and sleep-wake rhythm (22.1%). Rizzo asserts that these findings indicate that anxiety, sensory-responsivity, and GI issues are interrelated phenomena for people with autism (38:50).

• Anxiety, Sensory Over-Responsivity, and Gastrointestinal Problems in Children with Autism Spectrum Disorders (Mazurek et al., 2013)

Implications for clinical practice

Outside of autism, the gut microbiome is central to the prevention and care of type two diabetes, cardiovascular diseases, liver disease, hyperlipidemia, and many other conditions (34:50). Understanding the integral role of the gut microbiome in systems across the body must be a priority for clinical research and practice (40:28). Rizzo concludes that the development of the microbiota field must involve cardiologists, allergists, psychiatrists, and other specialists concerned with pathological conditions (40:43). He provides thanks before the Q&A session where he discusses chronic inflammation, biological food groups, and much more (41:45)

Kelly Barnhill, MBA, CN, CCN, summarizes emerging research on nutritional approaches and supports for autistic people. She outlines recent investigations on sensory processing and nutrition, dietary changes, and supplementation. The speaker discusses recent systematic reviews, highlighting general consensus and gaps in research. Barnhill describes several ongoing studies and future avenues of investigation before the Q&A session.

In this webinar: 

1:30 – Goals and objectives
2:45 – Critical aspects of current discourse
5:28 – Sensory processing and diet
9:15 – Dietary changes
13:40 – Dietary supplements
14:30 – Systematic reviews and meta-analyses
19:00 – Significant findings from the last year
22:00 – Ongoing and future research
29:03 – Q&A

Current discourse and recent publications

Barnhill outlines presentation goals and objectives and highlights the challenges faced by researchers during the COVID-19 pandemic before diving into research updates (1:30).

She summarizes a study that found that 43 autistic participants had significantly higher histamine and lower thiamine than non-austic controls. The speaker asserts that these findings suggest the need for further research into potential interventions and screenings that target these biomarkers (2:45). A study on the impact of dietary quality on executive function found a correlation between poor dietary quality (high intake of processed carbohydrates) and impaired working memory, executive function, and organizational skills (3:58). Barnhill states that dietary factors impact development trajectories and that improving diet quality can improve educational outcomes (4:25). 

Sensory processing and nutrition

The presenter summarizes a study that found autistic children exhibit higher sensory sensitivity to food than their non-autistic peers. Study data also showed lower levels of calcium and vitamin D in the autistic group compared to non-autistic controls. These findings, she continues, reinforce the clinical perspective of food sensitivity in autism, which also emphasizes the impact these sensitivities have on food choices and eating aversions (5:28).

Barnhill cites a study that revealed family units of individuals with food sensitivities also present with different eating profiles (6:00). Another sensory study on BMI found that almost 60% of participants met units for being overweight, and 12% met criteria for thinness or failure to thrive (7:00). These and other studies show autistic children have different eating and feeding styles than non-autistic controls. Barnhill notes that a lot of work is being done to profile how autistic children participate in feeding environments, what their preferences may look like, and appropriate interventions (8:00). 

Dietary changes and supplements

Barnhill explains that a growing body of evidence supports dietary changes and vitamin supplementation in autism. A study involving 400 males and 130 females across multiple facilities in the UK tracked nutrition and development over time. Results showed that adopting a ketogenic diet, with professional support, can be a feasible and appropriate intervention for autistic children (9:15). The speaker cites a survey study that revealed no significant differences in routine while starting a ketogenic diet and that it is easy to assist children in starting the diet if necessary (11:00). Barnhill suggests screening for autism in children who present with significant feeding disorders. 

The speaker describes two animal model studies examining the effect of ketogenic diets on mouse behavior. The first study found that mice on ketogenic diets had reduced social and cognitive deficits and repetitive behaviors and an increased abundance of beneficial microbes in the gut, with no adverse side effects reported. A second study found similar results and also indicated that ketogenic diets may restore histone balances in affected mice (12:15). A third mouse model that tested zinc supplementation saw improvements in social interaction and fear but had no effect on social novelty, or the initiation of new circumstances (13:40).

Systematic reviews and meta-analyses

Barnhill presents a review that found low choline and B vitamins and abnormal amino acids in autistic children compared to non-autistic groups (14:50). Another review on probiotic supplementation found evidence that dietary change can increase oxidative stress. The presenter suggests monitoring oxidative stress as a mark of microbiome changes in the future (16:05). Clinical literature reviews assert that autistic individuals are often deficient in vitamins A, C, B6, and B12. Across reviews of gluten-free/casein-free (GF/CF) diets, there is consensus that GF/CF diets are quite feasible and carry few adverse effects (17:03). Barnhill highlights a review of dietary interventions by Amadi et al. as an excellent source for big picture concepts and detailed questions (18:23). 

The speaker highlights significant studies from the last year that looked at nutrients/probiotics as anti-inflammatories/modulators (19:00), prenatal diets as a modifier for environmental risk factors for autistic traits (19:50), and assessment and data collection methods across studies (20:35). She explains that to best represent typical dietary intake, three-day real-time collection across weekdays and weekends is needed (21:22). 

Ongoing and future research

Barnhill outlines an ongoing study in Florida that explores the impact of eating program interventions (22:25). She also highlights an ongoing longitudinal study assessing the effect of therapeutic GF/CF diet and physiotherapy on the gross motor and cognition of autistic children (23:18). Enrollment is currently open for another exciting study that looks at using folic acid to promote language development (24:01). Finally, the first large study on the impact of mitochondrial function and nutrient intervention is also currently being conducted (25:31). These studies, the speaker asserts, represent a continuous efforts to advance our understanding of autism and identify targeted interventions. 

Barnhill considers future avenues of research and underscores that the most significant barrier to nutritional research is a lack of funding. Contemporary research, she continues, should focus on targeted dietary intakes and anti-inflammatory factors. While GF/CF diets are feasible and effective, she warns against having tunnel vision and reminds viewers that we must always consider more than one avenue (26:30). 

Q & A

During the Q&A (29:03), Barnhill discusses picky eating and nutrition in adulthood (31:40), feeding therapy and dietary changes (36:00), paleo diets and multivitamins (38:00), and Celiac and autoimmune diseases in autism (44:50). She also considers good sources for protein (51:45), vitamins (55:15), and multivitamins (57:05).

Vicki Kobliner, RDN, CD-N, describes nutritional and lifestyle strategies for improving sleep and overall health for autistic people. She discusses circadian rhythm and balancing cortisol and melatonin cycles throughout the day. The speaker considers screen time restrictions, environmental adjustments, and relaxation techniques that assist with sleep onset and quality. Kobliner emphasizes the connection between diet and sleep and highlights critical nutrients for balanced sleep cycles. She lists valuable herbs and supplements and summarizes the presentation before the Q&A. 

Handouts are online HERE (.pdf)

In this webinar: 

1:35 – Sleep
5:36 – Circadian Rhythm
7:36 – Lifestyle and sleep
11:30 – Journaling and relaxation
16:20 – Nutrition and sleep
18:10 – Carbs, melatonin, and vitamin D
21:30 – Magnesium and B vitamins
23:49 – Amino acids
26:45 – Herbs and supplements for sleep
33:46 – Adaptogens
36:18 – Summary
37:40 – Q&A

Sleep cycles and circadian rhythm

Kobliner outlines recommended sleep times (total length of sleep) for different age groups and notes that lack of sleep leads to impulsivity, attention deficits, forgetfulness, learning deficits, obesity, impaired immune function, anxiety, and depression in both children and adults (2:30). Circadian Rhythm, the speaker continues, is a cycle maintained by the body that influences the balances of cortisol and melatonin throughout the day. She highlights that healthy sleep patterns, or balanced cortisol and melatonin cycles, are associated with benefits to mental health, cognition, and development (5:36). 

How lifestyle affects sleep cycles

The speaker discusses several aspects of lifestyle and how they affect sleep patterns. For example, you must decrease your core temperature by two or three degrees to initiate and maintain sleep. Kobliner suggests taking a hot shower 60 – 90 minutes before bed or wearing socks to sleep to support radiation of heat through the extremities, thus cooling the body (7:36). Upon entering sleep, she continues, cortisol levels should be at their lowest, so winding down before bed is important (8:40). Some common techniques for winding down include avoiding electronics one to two hours before bed, stretching/relaxing body movements, and meditation (10:20). Kobliner discusses the correlation between gratitude journals and sleep quality, noting that research shows a 50% decrease in sleep onset in those who journal (11:30). 

To ensure sleep-supportive lighting, the presenter suggests avoiding LED, dimming the lights an hour or so before bed, using sleep masks, and eliminating blue wavelength light (from screens), which shuts off melatonin production (12:00). Kobliner recommends not eating within three hours of sleep to regulate body temperature and emphasizes the importance of consistent bedtimes (13:40). Exercise should be done earlier in the day and not less than 2 hours before bed because it can raise cortisol levels and increase core temperature (14:40). The presenter notes typical consequences of sleep obstruction including apnea, snoring, daytime fatigue, and attention deficit, among others (15:20). 

How nutrition affects sleep cycles 

Kobliner outlines research showing that a lack of crucial nutrients like calcium and magnesium, as well as vitamins A, C, D, E, and K, are associated with sleep problems. Nutrient consumption affects circadian hormonal pathways, making diet a critical aspect of balanced sleep cycles (16:20). Carbohydrates support melatonin production but can also increase time to sleep and drowsiness. Therefore, the speaker states, carbs should be consumed three to four hours before bed and should be whole grain, not processed (18:10). Calcium is necessary to convert tryptophan to melatonin and can be found in dairy, boned fish, almonds, broccoli, and sesame seeds. Deficiencies in vitamin D, which can be absorbed from sunlight, egg yolk, and fatty fish, are linked to insomnia (20:28). 

The presenter explains that magnesium supports neurotransmitter production, reduces restless leg syndrome, makes it easier to fall asleep, and improves sleep quality. Good sources of magnesium include leafy greens, nuts, seeds, whole grains, and soy (21:30). Vitamins B6 and B12 are necessary for melatonin production. Kobliner emphasizes balanced vitamin B levels, highlighting that deficiencies are linked to insomnia and depression while high doses are not safe. Sources for B6 include bananas, carrots, spinach, potatoes, eggs, fish, whole grains, milk and cheese. B12 can be absorbed from dairy, eggs, meat, fish, and shellfish (22:45). 

Amino acids are proteins’ building blocks, and some are critical to sleep. For example, tryptophan turns into serotonin, which ultimately turns into melatonin. Therefore, Kobliner asserts that we need to support this pathway with the food we eat. She lists some foods that support healthy sleep, including eggs, fish, peanuts, pumpkin seeds, tofu, and more (23:49). All of these foods are highlighted in the Mediterranean diet, which the speaker repeatedly notes as supportive of sleep. Other crucial amino acids include GABA and L-TEHTANINE, which work together to reduce anxiety, time to sleep, and overall sleep quality (25:49).

Herbs and supplements for sleep

Kobliner outlines potential melatonin doses and comments on its long-term use (26:45). She lists herbs and supplements that support sleep, noting specific qualities for each: valerian (28:40), lemon balm (29:09), Zyziphus (jujube) (30:08), passion flower (30:45), chamomile (31:15), skullcap (31:44), and lavender (32:20). 

Adaptogens are compounds that help our bodies deal with stress (33:46). Stress medications are often one way, meaning they reduce stress but then may keep the stress response from acting appropriately overall. However, adaptogenic herbs support and improve the body’s stress resilience and, because stress induces cortisol production, positively affect sleep cycles and quality (34:45). Kobliner highlights three adaptogenic herbs and their benefits to sleep: Rhodiola, ashwagandha, and holy basil (tulsi) (35:00). 

The speaker summarizes her presentation, reiterating the importance of circadian rhythm and balanced cortisol and melatonin cycles. She reminds viewers that poor sleep affects everything from energy to blood sugar to hormonal balance. Lifestyles, including diet, should aim at reducing stress and modulating cortisol to enhance sleep onset, duration, and quality. She notes that all of this can seem overwhelming and recommends starting with the “low-hanging” fruit or changes that are easier to implement (e.g., electronic schedules, bedtime snacks, adding protein to the diet) (36:18). During the Q&A the speaker discusses sources for essential nutrients, strategies for relaxing before sleep, and much more (37:40). 

Originally published March 2, 2022.