Effects of Ramadan and Non-ramadan Intermittent Fasting on Gut Microbiome

Abstract

BackgroundIn recent years, intermittent fasting (IF) has gained popularity in the health and wellness in the world. There are numerous types of IF, all of which involve fasting periods that last longer than an overnight fast and involve limited meal time-windows, with or without calorie restriction. The objective of this review is to summarize the current evidence for the effects of Ramadan and non-Ramadan IF on gut microbiome.MethodsWe explored PubMed, Scopus, Web of Science, and Google Scholar according to the PRISMA criteria (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). Animal and human studies were screened and reviewed separately by two researchers.ResultsTwenty-eight studies were selected after screening. Some of the studies were performed on animal models and some on humans. The results of these studies indicate a significant shift in the gut microbiota, especially an increase in the abundance of Lactobacillus and Bifidobacteria following fasting diets. The results of some studies also showed an increase in the bacterial diversity, decrease inflammation and increased production of some metabolites such as short-chain fatty acids (SCFAs) in individuals or samples under fasting diets. Moreover, Ramadan fasting, as a kind of IF, improves health parameters through positive effects on some bacterial strains such as Akkermansia muciniphila and Bacteroide. However, some studies have reported adverse effects of fasting diets on the structure of the microbiome.ConclusionIn general, most studies have seen favorable results following adherence from the fasting diets on the intestinal microbiome. However, because more studies have been done on animal models, more human studies are needed to prove the results.

Review of the Literature on Ramadan Fasting and Health in 2022

“…This landscape view of interconnected dietary behaviors, microbiota, and metabolites contributes to the future development of personalized, diet-based therapeutic strategies for gut-related disorders. Mousavi et al 54 summarized the current evidence for the effects of RF and non-Ramadan IF on the gut microbiome. Animal and human studies were screened and reviewed separately by two researchers.…”

Religious fasting and its impacts on individual, public, and planetary health: Fasting as a “religious health asset” for a healthier, more equitable, and sustainable society

“…Of the 27 included reviews, only one systematic review ( 21 ) and a scoping review ( 22 ) evaluated the effects of Orthodox fasting on health/nutritional outcomes. The remainder reviews ( n = 25) focused on the effects of Ramadan fasting on anthropometric and metabolic markers ( 23 – 25 ), glucometabolic parameters ( 26 – 29 ), salivary flow rate, inflammatory and metabolic variables ( 30 ), immunity, inflammatory markers and infectious events ( 31 – 33 ), blood pressure and cardiovascular events ( 34 – 36 ), liver function ( 37 ), renal function and chronic kidney diseases ( 38 , 39 ), body mass (i.e., body weight) and body composition ( 40 – 42 ), intestinal microbiome changes ( 43 ), hormones regulating appetite and satiety ( 44 ), psychiatric parameters ( 45 ), sleep quality ( 46 ) and pregnancy outcomes ( 47 ). The characteristics and the main outcomes of the included reviews are presented in Table S2 .…”

“…Some findings have revealed that fasting diets can also cause changes in the microbiome ( 129 , 130 ). In a recent systematic review, Mousavi et al ( 43 ) reported that Ramadan fasting improves health parameters through positive effects on some bacterial strains such as Akkermansia muciniphila and Bacteroide .…”

Targeted metabolomics reveals plasma short-chain fatty acids are associated with metabolic dysfunction-associated steatotic liver disease

“…Therefore, fasting can impact SCFA concentrations in the blood. The duration of fasting, dietary differences, use of probiotics, and medication could potentially affect our results including differences between patients with MASLD and controls [ 32 – 34 ]. There is no clear evidence showing the effect of diet or medication on SCFAs but a systematic review found no clear effect of supplementary dietary fibers on SCFA levels [ 34 ].…”