Effect of lactulose intervention on gut microbiota and short chain fatty acid composition of C57BL/6J mice

Abstract

Gut microbiota have strong connections with health. Lactulose has been shown to regulate gut microbiota and benefit host health. In this study, the effect of short-term (3 week) intervention of lactulose on gut microbiota was investigated. Gut microbiota were detected from mouse feces by 16S rRNA high-throughput sequencing, and short chain fatty acids (SCFAs) were detected by gas chromatography-mass spectrometry (GC-MS). Lactulose intervention enhanced the α-diversity of the gut microbiota; increased the abundance of hydrogen-producing bacteria Prevotellaceae and Rikenellaceae, probiotics Bifidobacteriaceae and Lactobacillaceae, and mucin-degrading bacteria Akkermansia and Helicobacter; decreased the abundance of harmful bacteria Desulfovibrionaceae and branched-chain SCFAs (BCFAs). These results suggest that lactulose intervention effectively increased the diversity and improved the structure of the intestinal microbiota, which may be beneficial for host health.

Keywords: 16S rRNA high-throughput sequencing; gut microbiota; prebiotic; probiotics; short chain fatty acids.

Figure 1

DNA sequences data and OTUs‐based community compositions in fecal microbiota before and after lactulose intervention. (a) Venn diagram of the OTUs for the CG, EG. Numbers indicated the number of OTUs that were unique and the number shared (core) by two or more groups, as depicted by no‐intersecting and intersecting ellipses, respectively. (b) Rarefaction analysis of the 32 different communities. (c) Species accumulation curves of the 32 different communities. (d) Variations of microbiota in CG and EG by PCoA analysis. (e) Unweighted‐pair group method with arithmetic mean tree of all subjects. CG, control group, n = 10; CG1, control group, week 0; CG2 control group, 3rd week; EG, experimental group, n = 6; EG1, experimental group, week 0; EG2, experimental group, 3rd week

Figure 2

α‐diversity of C57BL/6J mice fecal microbiota after lactulose intervention for 3 weeks. Microbial richness estimates (ACE and Chao1) and diversity indices (Simpson and Shannon) were measured at OTUs definition of >97% identity. CG1, control group, week 0; CG2 control group, 3rd week, n = 10; EG1, experimental group, week 0; EG2, experimental group, 3rd week, n = 6. Data were analyzed by nonparametric test followed by Mann–Whitney U‐test. *p < .05

Figure 3

Fecal microbiota of mice before (left) and after (right) lactulose intervention. (a) The mean relative abundances of bacterial phyla in fecal samples before and after lactulose intervention. (b) The mean relative abundances of Lactobacillaceae and Bifidobacteriaceae before and after lactulose intervention. (c) The mean relative abundances of hydrogen‐producing bacterium before and after lactulose intervention. (d) The mean relative abundances of mucin‐degrading bacterium before and after lactulose intervention. (e) The mean relative abundances of Desulfovibrionaceae before and after lactulose intervention. EG1, experimental group, week 0; EG2, experimental group, 3rd week, n = 6. Data were analyzed by nonparametric test followed by Mann–Whitney U‐test. * p < .05

Figure 4

Mean concentrations of acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and total short chain fatty acids after lactulose intervention for 3 weeks. EG1, experimental group, week 0; EG2, experimental group, 3rd week, n = 6. Data were analyzed by nonparametric test followed by Mann–Whitney U‐test. * p < .05

Figure 5

Effect of lactulose on gut microbiota. Lactulose intervention increased hydrogen‐producing bacteria, probiotics, mucin‐degrading bacteria, decreased pathogenic bacteria and harmful metabolites in mice