Dietary patterns in childhood and their effect on gut microbiota – an Asian perspective on atopy risk

Title: Dietary patterns in childhood and their effect on gut microbiota – an Asian perspective on atopy risk

A group of medical professionals specialized in paediatric allergy, paediatric immunology and paediatric gastroenterology from Malaysia and Singapore as well as microbiome scientists from Danone Research & Innovation recently published a perspective article commenting on the connection of dietary patterns, early life microbiome and the development of paediatric allergy¹. In the Journal of Allergy and Clinical Immunology, the authors summarize how nutrition, especially traditional Asian diets, could prevent atopy and how the early life microbiome plays an influential part in reducing atopy risk.

The prevalence of atopic disorders has risen in various parts of the world, including Asia. Cohort studies, following Asians migrating to Western countries as well as other epidemiological studies imply that a Westernized environment is associated with loss of gut microbiota diversity and microbes with the ability to digest the fibers present in plant-based foods.

The authors therefore reviewed existing evidence and they concluded that strong evidence supports the hypothesis that a traditional Asian diet may reduce atopy risk.

What is a traditional Asian diet?

Traditional Asian diet varies across the regions but is generally characterized by a high amount of fruits and vegetables, whole grains, legumes, nuts, seeds and soy food. Furthermore, moderate amounts of fish, poultry, eggs, yogurt and a low intake of meats and sweet are typical of the Asian diet. A unique component of traditional Asian diet is soy. Soy food has a high content of polyphenols with antioxidant, anti-inflammatory and anti-allergic properties. Furthermore, Asian diets often contain functional (fermented) food such as Kimchi (pickled cabbage), dahi (curd or yogurt) and tempeh (fermented soybean).

What is the role of nutrition and microbiota?

Both soy products and functional (fermented) food are a source of prebiotics and probiotics and impacts the gut microbiota. Soy consumption can for instance increase bifidobacteria and lactobacilli levels in the gut, as well as inhibit potentially pathogenic enterobacteria populations (enterobacteria is a group of bacteria that encompasses some opportunistic pathogens).

Traditional Asian food cultures further promote diverse microbial exposure through food practices such as communal dining and eating with hands, as well as through specific food processing procedures such as fermentation. This in turn can contribute to increase the gut microbiome diversity and facilitate immune maturation (hygiene hypothesis).

Certain gut microbes can digest fibers which are ubiquitously present in plants. This can lead to the production of short-chain fatty acids (SCFAs), such as butyrate. Butyrate has been attributed with anti-inflammatory and immunomodulatory effects. In four large independent cohort studies (CHILD, PASTURE, PATCH and DIABIMMUNE) associations between high butyrate levels and lower likelihood of developing allergic diseases were found. This is further supported by findings that members of certain microbial families, including the genera Faecalibacterium (which can also produce butyrate) were associated with a reduced risk of atopy².In addition, a study investigating 63 infants from the ‘Growing Up in Singapore Toward healthy Outcomes’ (GUSTO) cohort revealed a delayed colonization by beneficial Bacteroides fragilis and subsequent delayed accumulation of butyrate in allergen-sensitized atopic eczema infants³.

Based on such findings, it is plausible that dietary interventions leading to increasing SCFA-producing gut microbes and/or butyrate concentrations could in turn reduce atopy risks in children. Examples of such dietary interventions could be resistant starch, butyrate-containing foods (e.g. ghee used in South Asian cooking) and live biotherapeutics.

In addition, implementing new dietary standards of care for infants, such as the timely introduction of potentially allergenic proteins (at 4-6 months of age) and offering a diverse diet when introducing solid food, may also greatly assist with preventing allergy development.

The authors conclude that numerous observational studies underscore the important relationship between the diet, microbiota and disease but that these are by itself not sufficient to establish guiding clinical practices. Well-designed human intervention trials are urgently needed to establish causal relationships and to elaborate on the dosing, timing and duration of interventions. Furthermore, insufficient knowledge about the gut microbiota profile and dietary patterns of Asian children hampers the creation of next-generation pre- and probiotic cocktails which could repopulate or preserve favourable living microbes in the microbiome. For now, a plant-based, culturally adapted Asian diet which can promote a favourable microbiome, is desirable to mitigate atopy risk in children.

Such a plant-based diet resonates with Danone’s “One Planet. One Health” vision, taking a holistic view at the connectivity of people’s health and the planet’s health.

Please read the full publication here: https://www.jacionline.org/article/S0091-6749(20)31175-1/fulltext

Pioneering nutritional solutions

At Danone Nutricia Research we believe that healthy, non-allergic infants acquire oral tolerance, a state in which the immune system recognises food allergens as harmless and does not respond to the food allergen; this is an active physiological process during the development of the immune system.

In line with scientific evidence⁴, we support the hypothesis that controlled exposure to allergens is better than complete avoidance for a majority of infants, except for those with severe allergies for whom any exposure poses a safety risk.

References:

1 Ismail IH, et al. Dietary patterns in childhood and their effect on gut microbiota – an Asian perspective on atopy risk, Journal of Allergy and Clinical Immunology (2020), doi: https://doi.org/10.1016/j.jaci.2020.05.057.

2 Galazzo G, et al. Development of the Microbiota and Associations With Birth Mode, Diet, and Atopic Disorders in a Longitudinal Analysis of Stool Samples, Collected From Infancy Through Early Childhood, Gastroenterology (2020), doi: 10.1053/j.gastro.2020.01.024.

3 Ta LDH, et al. A compromised developmental trajectory of the infant gut microbiome and metabolome in atopic eczema, Gut Microbes (2020), https://doi.org/10.1080/19490976.2020.1801964

4. Anagnostou, K., et al. Archives of Disease in Childhood, 2014. 0: p. 1-5.