Gut Microbes (Dec 2023)

Effect of synbiotic supplementation on immune parameters and gut microbiota in healthy adults: a double-blind randomized controlled trial

  • Xiaoqin Li,
  • Shan Hu,
  • Jiawei Yin,
  • Xiaobo Peng,
  • Lei King,
  • Linyan Li,
  • Zihui Xu,
  • Li Zhou,
  • Zhao Peng,
  • Xiaolei Ze,
  • Xuguang Zhang,
  • Qiangchuan Hou,
  • Zhilei Shan,
  • Liegang Liu

DOI
https://doi.org/10.1080/19490976.2023.2247025
Journal volume & issue
Vol. 15, no. 2

Abstract

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ABSTRACTSynbiotics are increasingly used by the general population to boost immunity. However, there is limited evidence concerning the immunomodulatory effects of synbiotics in healthy individuals. Therefore, we conducted a double-blind, randomized, placebo-controlled study in 106 healthy adults. Participants were randomly assigned to receive either synbiotics (containing Bifidobacterium lactis HN019 1.5 × 108 CFU/d, Lactobacillus rhamnosus HN001 7.5 × 107 CFU/d, and fructooligosaccharide 500 mg/d) or placebo for 8 weeks. Immune parameters and gut microbiota composition were measured at baseline, mid, and end of the study. Compared to the placebo group, participants receiving synbiotic supplementation exhibited greater reductions in plasma C-reactive protein (P = 0.088) and interferon-gamma (P = 0.008), along with larger increases in plasma interleukin (IL)-10 (P = 0.008) and stool secretory IgA (sIgA) (P = 0.014). Additionally, synbiotic supplementation led to an enrichment of beneficial bacteria (Clostridium_sensu_stricto_1, Lactobacillus, Bifidobacterium, and Collinsella) and several functional pathways related to amino acids and short-chain fatty acids biosynthesis, whereas reduced potential pro-inflammatory Parabacteroides compared to baseline. Importantly, alternations in anti-inflammatory markers (IL-10 and sIgA) were significantly correlated with microbial variations triggered by synbiotic supplementation. Stratification of participants into two enterotypes based on pre-treatment Prevotella-to-Bacteroides (P/B) ratio revealed a more favorable effect of synbiotic supplements in individuals with a higher P/B ratio. In conclusion, this study suggested the beneficial effects of synbiotic supplementation on immune parameters, which were correlated with synbiotics-induced microbial changes and modified by microbial enterotypes. These findings provided direct evidence supporting the personalized supplementation of synbiotics for immunomodulation.

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