Impact of smoking cessation, coffee and bread consumption on the intestinal microbial composition among Saudis: A cross-sectional study

Abstract

The gut microbiota is often affected by the dietary and lifestyle habits of the host, resulting in a better efficacy that favors energy harvesting from the consumed food. Our objective was to characterize the composition of gut microbiota in adult Saudis and investigate possible association with lifestyle and dietary practices. Feces from 104 Saudi volunteers (48% males) were tested for microbiota by sequencing the V3-V4 region of bacterial 16S ribosomal RNA (rRNA). For all participants, data were collected related to their lifestyle habits and dietary practices. The relative abundance (RA) of Fusobacteria was significantly higher in normal weight Saudis (P = 0.005, false discovery rate-FDR = 0.014). Individuals who consumed more coffee presented marginally significant more RA of Fusobacteria (P = 0.02, FDR = 0.20) in their gut microbiota compared to those reporting low or no coffee intake, but the RA of Fusobacteria was significantly higher in smokers compared to nonsmokers (P = 0.009, FDR = 0.027). The RA of Fusobacteria was also significantly higher in those reporting daily consumption of bread (P = 0.005, FDR = 0.015). At the species level, the gut microbiota of people who consumed coffee was dominated by Bacteroides thetaiotaomicron followed by Phascolarctobacterium faecium and Eubacterium rectale. Similarly, the gut microbiota of smokers was also enriched by B. thetaiotaomicron and Lactobacillus amylovorus. Smoking cessation, bread and coffee consumption induce changes in the intestinal microbial composition of Saudis.

Gut Microbiome Composition in Obese and Non-Obese Persons: A Systematic Review and Meta-Analysis

“…Of the 32 included studies, 25 studies investigated alpha diversity in obese versus non-obese adults, two did not assess alpha diversity, and five studies did not report alpha diversity stratified by BMI ( Table 2 ). At the individual study level, results on the difference in alpha diversity between obese and non-obese persons were discrepant ( Figure 3 ): the Shannon index, reported in 22 studies, was found to be significantly lower in obese compared to non-obese adults in nine studies [ 17 , 32 , 35 , 37 , 41 , 46 , 48 , 51 , 54 ], higher in two studies [ 21 , 54 ], and not significantly different in eleven studies [ 19 , 33 , 34 , 35 , 39 , 44 , 45 , 47 , 49 , 52 , 53 ]. The study of Salah et al [ 54 ] found significantly lower diversity (Shannon index) among obese as compared to non-obese persons and higher diversity among obese diabetic compared to non-obese persons.…”

“…From a total of 2445 unique hits, 116 studies were selected for full-text review. Of these, 33 primary reports [ 17 , 18 , 19 , 20 , 21 , 32 , 33 , 34 , 35 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ], including 32 studies met the criteria for inclusion and were selected for data extraction and synthesis.…”

“…The database in which taxonomic binning of 16S reads were based on was not reported in three studies [ 32 , 40 , 53 ]. The rest of the studies mainly used the Greengenes database ( n = 17) [ 18 , 19 , 37 , 39 , 41 , 43 , 44 , 45 , 46 , 48 , 50 , 51 , 54 , 58 , 59 , 60 ], RDP ( n = 4) [ 20 , 34 , 52 , 55 ], SILVA ( n = 3) [ 35 , 47 , 54 ], NCBI ( n = 2) [ 38 , 57 ], or DB-BA9.0 ( n = 2) [ 17 , 21 ]. Other databases used were: Broad Institute Microbiome Utilities microbiomeutil-r20110519 database [ 33 ], KEGG (Kyoto Encyclopedia of Genes and Genomes) Orthology (KO) Database at level 2 and level 3 [ 54 ], HUMAnN2 v0.11.1 [ 55 ] for shotgun metagenomics, and UNITE reference database for fungal taxonomy [ 48 ] ( Figure 2 ).…”

“…A total of two studies used BMI < 30 as reference [ 20 , 57 ], nine studies used BMI < 25 [ 18 , 26 , 34 , 35 , 43 , 44 , 47 , 53 , 55 ], one study used BMI < 20 [ 21 ], fifteen studies used BMI 18.5–24.9 [ 19 , 32 , 33 , 41 , 45 , 46 , 48 , 49 , 51 , 52 , 54 , 56 , 58 , 59 , 60 ], and one study from Japan used BMI < 18.5 as a reference [ 17 ]. However, in general, studies from Asia used lower cut-offs than studies from Europe to define obesity.…”

Beverages intake and functional bowel disorders: A cross‐sectional study in first‐year undergraduates

“…First, drinking coffee is accompanied by an elevated relative abundance of gut microbiota such as Fusobacteria and Bacteroides thetaiotaomicron. 19 Second, caffeine, the main active ingredient in coffee, can directly promote the secretion of small intestinal fluid 20 and indirectly decrease fluid absorption by promoting the secretion of intestinal anions such as chloride through a variety of pathways. 21,22 It is interesting and worth exploring why a further increase in drinking coffee does not lead to an increased prevalence of FBD.…”