Thaung Han Myint
The human gut is home to trillions of microorganisms, collectively known as the gut microbiome. A diverse microbiome is associated with better digestive health, stronger immunity, improved metabolic function, and reduced risk of many chronic diseases. One of the most important factors influencing microbiome diversity is dietary fibre intake.
Fibre is the most profound nutrient deficiency we face.
Dietary fibre — the indigestible carbohydrate component of plants — is one of the most potent dietary modulators of the human gut microbiota. Despite strong evidence linking fibre intake to reduced chronic disease risk, the majority of individuals globally consume less than 20g per day, well below the recommended 25–29 g per day. 1,2
Fibre and Gut Microbiota Composition
Dietary fibre serves as the primary fermentable substrate for beneficial gut bacteria. A systematic review and meta-analysis of 64 randomized controlled trials (2,099 participants) demonstrated that fibre interventions significantly increased the abundance of Bifidobacterium spp. (SMD 0.64; 95% CI 0.42–0.86; P < 0.00001) and Lactobacillus spp. (SMD 0.22; 95% CI 0.03–0.41; P = 0.02) compared with placebo or low-fibre controls. 3
Population-based data from the FINRISK 2002 study (n = 4,930) confirmed that plant- and fibre-rich dietary patterns are associated with greater microbial alpha and beta diversity, with the strongest associations observed for fibre-rich breads, fruits, and vegetables. 4
Genera with fibre-degrading and short-chain fatty acid (SCFA)-producing capacities were positively associated with healthy food choice scores. 4
Cross-cultural comparisons further illustrate this relationship: children consuming a fibre-rich African diet harbor significantly higher proportions of Prevotella, Xylanibacter, and Butyrivibrio — genera equipped with genes for cellulose and xylan hydrolysis — compared with children consuming a Western diet. 5
Short-Chain Fatty Acid Production: The Key Mediator
The fermentation of dietary fibre by colonic microbiota produces SCFAs — primarily acetate, propionate, and butyrate – which serve as critical mediators of fibre’s health benefits.6,7 Butyrate is the preferred energy source for colonocytes and maintains gut epithelial integrity. Fibre interventions have been shown to increase fecal butyrate concentrations (SMD 0.24; P = 0.05), and specific fibre types such as inulin and arabinoxylan significantly increase total SCFA production. 3,8
SCFAs exert their effects through multiple pathways: activation of G-protein-coupled receptors (GPR41, GPR43, GPR109A) on intestinal epithelial cells and immune cells; inhibition of histone deacetylases (HDACs), leading to epigenetic modulation with anti-inflammatory effects; and stimulation of gut hormones including GLP-1 and peptide YY, which regulate appetite and glucose metabolism. 5,7 Through GPR43 signaling on white adipose tissue, SCFAs also influence lipid and glucose metabolism, contributing to a lean body habitus.5
Importantly, while fibre supplementation consistently raises total SCFA and acetate levels, individual differences in SCFA-producing microbes lead to significant variation in propionate and butyrate production, highlighting the importance of personalized approaches. 9
Health Outcomes: From Gut to Systemic Benefits
The downstream health effects of a high-fibre diet are extensive and well-documented. A landmark Lancet meta-analysis encompassing 135 million person-years of data from 185 prospective studies and 58 clinical trials demonstrated a 15–30% decrease in all-cause mortality, cardiovascular mortality, and incidence of coronary heart disease, stroke, type 2 diabetes, and colorectal cancer among the highest fibre consumers compared with the lowest. 1 Clinical trials confirmed that higher fibre intake reduces body weight, systolic blood pressure, and total cholesterol. 1
Beyond cardiometabolic and oncologic outcomes, fibre-derived SCFAs play a critical role in immune regulation. SCFAs increase regulatory T-cell numbers and function, enhance IL-10 production, activate the NLRP3 inflammasome, and decrease expression of inflammatory cytokines. 7 Insufficient fibre intake and reduced SCFA levels have been implicated in the rising prevalence of Western lifestyle diseases, including food allergy and asthma. 7
Fiber and Infection Resistance
Emerging evidence suggests that fibre-rich diets may also confer protection against enteric infections. In murine models, fibre-deficient diets were linked to prolonged Clostridioides difficile infection, while supplementation with inulin or fibre mixtures reduced C. difficile burden and supported microbial diversity that favored pathogen exclusion. 5
Conclusion
A high-fibre diet is a cornerstone of gut and systemic health. By serving as a fermentable substrate for beneficial microbes, dietary fibre promotes the production of SCFAs that regulate immune function, maintain gut barrier integrity, modulate metabolism, and reduce chronic disease risk.
Given that 94% of Americans do not meet adequate intake levels for dietary fibre, public health strategies should prioritize increasing fibre consumption through vegetables, fruits, whole grains, legumes, nuts, and seeds. 2
Dietary fibre, found in fruits, vegetables, legumes, whole grains, nuts, and seeds, cannot be digested by human enzymes. Instead, it serves as food for beneficial gut bacteria. When these microbes ferment fibre, they produce short-chain fatty acids such as butyrate, acetate, and propionate, which help maintain the intestinal barrier, reduce inflammation, and support overall health.
Different types of fibre nourish different groups of bacteria. Therefore, consuming a wide variety of fibre-rich foods promotes the growth of diverse microbial species. In contrast, a low-fibre diet can reduce microbial diversity and may encourage the growth of less beneficial bacteria.
Research consistently shows that populations consuming traditional plant-rich diets have greater gut microbiome diversity than those consuming highly processed, low-fibre diets. Increasing daily fibre intake through a variety of plant foods is a simple and effective strategy to support a healthy and resilient gut ecosystem.
For optimal gut health, adults should aim to consume at least 25–38 grams of fibre daily from diverse plant sources. Small dietary changes, such as adding beans, vegetables, fruits, and whole grains to meals, can have significant long-term benefits for microbiome health and overall well-being.
Common fibre-rich foods in Myanmar diets include beans, chickpeas, lentils, roselle leaves (chin baung ywet), pennywort, water spinach (kanzon ywet), bamboo shoots, eggplant, okra, and a wide variety of seasonal fruits. These foods provide soluble and insoluble fibre, which help maintain regular bowel movements and support digestive health.
Myanmar cuisine also includes fermented foods such as fermented tea leaves (laphet), fermented fish products, and fermented vegetables. These foods may introduce beneficial microorganisms and work together with dietary fibre to support a balanced gut ecosystem.
Some traditional Myanmar foods that are particularly beneficial for gut health include:
- Mohinga with added vegetables
- Bean and chickpea curries
- Roselle leaf dishes (chin baung ywet)
- Tea leaf salad (laphet thoke)
- Vegetable soups and mixed vegetable curries
- Fresh fruits such as guava, papaya, mango, and banana
As Myanmar dietary habits become increasingly influenced by processed foods that are often low in fibre, it is important to preserve traditional eating patterns. Consuming a variety of fibre-rich vegetables, legumes, fruits, and fermented foods can help maintain gut microbiome diversity and promote long-term health.
In conclusion, many traditional Myanmar foods naturally support gut health. By continuing to enjoy these fibre-rich foods, people can nourish their gut microbiome and reduce the risk of chronic disease while preserving an important part of Myanmar’s culinary heritage.
References
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Simpson HL, Campbell BJ. Alimentary Pharmacology & Therapeutics. 2015;42(2):158-79. doi:10.1111/apt.13248. - 9Dietary Fibers as Drivers of Short-Chain Fatty Acids Homeostasis: A Review of Intestinal Production, Systemic Distribution, and Inter-Individual Variation.
Fan S, Tu Z, Zhang Z, et al. Journal of Agricultural and Food Chemistry. 2026;74(11):8948-8970. doi:10.1021/acs.jafc.5c12022. - 10The Impact of Dietary Fiber Consumption on Human Health: An Umbrella Review of Evidence From 17,155,277 Individuals. Veronese N, Gianfredi V, Solmi M, et al. Clinical Nutrition (Edinburgh, Scotland). 2025;51:325-333. doi:10.1016/j.clnu.2025.06.021.
Author Information
Dr Thaung Han Myint MD
Primary Care PhysicianM
Plant City, FL , USA
