In a recent study published in Frontiers in Microbiology, scientists from the Acibadem Mehmet Ali Aydinlar University in Istanbul, Turkey, explore the impact of Ramadan intermittent fasting on the composition of the gut microbiota.

Study: Effects of Ramadan intermittent fasting on gut microbiome: is the food plan key? Image Credit: Baramyou0708 / Shutterstock.com

Background

The human gastrointestinal (GI) microbiome is comprised of trillions of microorganisms. Bacteroidetes and Firmicutes are essentially the most abundant bacterial species within the GI tract, followed by Proteobacteria, Verrucomicrobia, Fusobacteria, and Actinobacteria.

The gut microbiome composition typically stays stable throughout maturity. Nevertheless, the microbiota might be affected by various aspects starting from age, dietary habits, and physical exertion to body mass index (BMI) and genetics.

Weight loss program is probably the most significant aspects influencing the composition of the gut microbiota. Previous studies have reported that while the Western-style food plan reduces the proliferation of helpful bacterial populations inside the gut, the Mediterranean food plan differs significantly in its effects on the gut microbiome, because it maintains the balance between helpful and harmful bacterial populations.

Fasting can be a vital factor that may considerably influence the gut microbiota composition. Fasting is defined as voluntary food deprivation for therapeutic, cultural, or political reasons. Ramadan intermittent fasting is a time-restricted feeding pattern wherein food and liquid consumption is restricted from dawn to sunset during the complete month of Ramadan, which occurs in the course of the ninth month of the Muslim calendar.

Previous studies investigating dietary patterns indicate that intermittent fasting can alter gut microbiota composition, increase short-chain fatty acid (SCFA) production within the GI tract, and reduce a person’s risk of certain cardiovascular and metabolic diseases.

Study design

In the present study, scientists investigate the consequences of Ramadan intermittent fasting on the gut microbiota composition within the Turkish Muslim population.

The present study included 12 healthy adults who practiced 15 hours of fasting day by day for 29 consecutive days during Ramadan. All study participants were asked to follow their routine diets and avoid exercise in the course of the study period.

Anthropometric measurements, including body weight and height, three-day dietary records, and fecal samples, were collected from the participants the day before Ramadan fasting initiation, denoted because the baseline time point, in addition to after the completion of Ramadan fasting.

Three-day dietary record data were used to evaluate food intake in the course of the study period. Fecal samples were analyzed by 16S ribosomal ribonucleic acid (rRNA) gene sequencing and bioinformatics to find out any potential changes within the gut microbiota composition.

Altered gut composition after fasting

The evaluation of the gut microbiota composition revealed that Ramadan intermittent fasting significantly enhanced the alpha and beta diversity of gut microbiota on the phylum level. Nevertheless, on the genus level, fasting-induced changes were more heterogeneous amongst participants.

On the phylum level, a discount in Firmicutes and induction in Proteobacteria were observed at the tip of fasting as in comparison with baseline levels. Induction within the Bacteroidetes/Firmicutes ratio was also observed amongst participants at the tip of Ramadan fasting.

On the genus level, reduced levels of seven bacterial genera, including Blautia, Coprococcus, Dorea, Faecalicatena, Fusicatenibacter, Lachnoclostridium, and Mediterraneibacter were observed at the tip of the fasting period. Comparatively, increased levels of two bacterial genera of Escherichia and Shigella were observed at this same time point in fasting individuals.

Impact of dietary intake

The correlation evaluation between dietary composition and gut microbiota diversity revealed that carbohydrate-enriched diets were related to reduced genera diversity. Comparatively, high-fat diets were related to more diverse genus composition.

Further evaluation between the dietary intake and relative abundance of bacteria on the genus level revealed negative correlations between protein consumption and Ihubacter, vegetable consumption and Fusicatenibacter, and nut consumption and Intestinibacter. The truth is, nut consumption was found to affect six out of the 13 detected genera.

Study significance

Intermittent fasting during Ramadan is related to wealthy and diverse gut microbiota. Importantly, significant differences in food consumption habits were observed amongst study participants; nonetheless, the duration of fasting was similar.

The observed changes within the gut microbiota are likely attributable to the differences in consumed foods. Thus, future studies that include individuals who follow similar dietary practices during Ramadan are needed to find out the effect of intermittent fasting on the composition of the gut microbiota more precisely.