Subfractional Spectrum of Serum Lipoproteins and Gut Microbiota Composition in Healthy Individuals

Aim: To reveal the relationship between gut microbiota composition and subfractional spectrum of serum lipoproteins and metabolic markers in healthy individuals from Moscow. Methods: The study included 304 participants (104 were men), who underwent thorough preclinical assessment to exclude any chronic disease as well as cardiovascular pathology. Lipoprotein subfractional distribution was analyzed by Lipoprint LDL System (Quantimetrix, Redodno Beach, CA, USA). Gut microbiota composition was assessed by 16S rRNA sequencing of V3-V4 regions. Results: High gut microbiota diversity was positively associated with HDL-cholesterol (C) level and negatively associated with abdominal obesity, BMI, and dyslipidemia. According to selbal analysis, excessive representation of Prevotella spp. was positively associated with IDL-C and LDL-2-C. VLDL-C correlated with Ruminococcus_u/Faecalibacterium_prausnitzii balance. An unexpected positive relationship between LDL-C level and Bifidobacteriaceae_u/Christensenellaceae_u to Bifidobacterium_u balance was found, which may reflect the importance of the integrative microbiota assessment. Low microbiota diversity was associated with obesity, abdominal obesity and low HDL-C level. Conclusions: Gut microbiota imbalance may be one of the components involved in metabolic disorders. The balance of microorganisms and the microbiota diversity may play a more significant role in human health than individual bacterial genera.

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The Effects of Increasing Intake of Intact Wheat Fibre or Wheat Bran on Gut Microbiota Diversity: a Systematic Review

Proceedings of The Nutrition Society ◽

10.1017/s0029665120004802 ◽

2020 ◽

Vol 79 (OCE2) ◽

Author(s):

Angie Jefferson ◽

Katie Adolphus

Keyword(s):

Systematic Review ◽

Gut Microbiota ◽

Wheat Bran ◽

Bacterial Species ◽

Microbiota Composition ◽

Inclusion Criteria ◽

Breakfast Cereal ◽

High Fibre ◽

Microbiota Diversity ◽

Gut Microbiota Composition

AbstractThe influence on health of the human gut microbiota is increasingly recognised, however wheat fibre, consumed frequently in Western diets has traditionally been considered inert with regard to gut microbiota composition and metabolic activity. We undertook a systematic review (PRISMA methodology) of human intervention studies examining the effects of intact cereal fibres on gut microbiota composition among healthy adults.(1) Studies published in the past 20 years were identified on PubMed and Cochrane electronic databases. Inclusion criteria were: healthy adult participants, at least one intact cereal fibre (or its sub-fraction) and measurement of faecal microbiota related outcomes. Out of forty studies meeting inclusion criteria, seventeen manipulated wheat fibre/bran or its key constituent arabinoxylans (AXOS), and ten used a whole diet approach with predominantly wheat fibre. Results from these twenty seven wheat fibre papers are presented here. Eight studies provided wheat bran/fibre (ranging from 5.7g-21g/day wheat fibre or 13g-28g/day wheat bran). Three reported significant effects on gut microbiota abundance and/or diversity (both at phyla and species level) and one showed no effect. Six reported significant increases in fermentation metabolites and one reported no significant change. Ten studies manipulated whole day fibre intake (predominantly wheat but also permitting some oats, rye and rice). Wholegrain intake ranged from 80g-150 g per day and fibre from 13.7g–40 g per day. Six found significant increases in bacterial diversity and/or abundance and five showed significant increases in fermentation metabolites. Two identified that response to high fibre intervention is dependent on baseline gut microbiota richness - those with limited richness exhibiting greater microbiota change over time in response to fibre increase. Two reported no significant effects. Nine studies utilised manipulation of AXOS (2.2g–18.8 g per day) with five demonstrating significant increases in target bacterial species and six significant increases in fermentation metabolites. One reported no significant effect to faecal metabolites. This review supports a role for the wheat fibre found in everyday foods (such as bran breakfast cereal of high fibre breads) promoting both microbiota diversity and abundance. While the healthy microbiome is yet to be defined, consumption of a single daily serving of wheat bran fibre appears sufficient to effect gut microbiota fermentation (with demonstrable effects arising from as low as 6g/day), and promote species diversity, with potential benefit to health.However exploration of stability over longer time frames (> 12 weeks) is now required.

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Trem-2 modulation of gut microbiota is blunted during hepatotoxic injury and uncoupled from liver repair responses

10.1101/857078 ◽

2019 ◽

Author(s):

Inês Coelho ◽

Nádia Duarte ◽

Maria Paula Macedo ◽

Carlos Penha-Gonçalves

Keyword(s):

Gut Microbiota ◽

Liver Damage ◽

Liver Tissue ◽

Innate Immune ◽

Microbiota Composition ◽

Wild Type ◽

Immune Receptors ◽

Microbiota Diversity ◽

Gut Microbiota Composition

AbstractThe involvement of gut microbiota in liver disease has been addressed in the context of the “leaky gut hypothesis” postulating that dysbiosis allow microbial components to elicit liver inflammatory responses and hepatic tissue damage. Conversely, commensal gut microbiota acting on innate immune receptors protect against hepatotoxic insults. Given that mice deficient for the triggering receptor expressed on myeloid cells-2 (Trem-2) show increased vulnerability to experimental drug-induced hepatic damage we explored the possibility that Trem-2 is a modulator of gut microbiota composition.We found that microbiota composition in untreated Trem-2 KO mice differs from the wild-type showing overall decrease in microbiota diversity and increased representation of Verrucomicrobia. Interestingly, induction of liver damage with hepatotoxic drugs blunted this microbiota diversity difference and altered phyla composition with increased representation of Verrucomicrobia during acute hepatic injury and Proteobacteria during chronic challenge. Furthermore, co-housing experiments that homogenized microbiota diversity showed that the increased liver tissue vulnerability to hepatotoxic insults in Trem-2 KO mice was not dependent on microbiota composition. This work uncouples Trem-2 dependent alterations in gut commensal microbiota from Trem-2 pro-recovery effects in the damaged liver tissue. These findings support the possibility that unlinked actions of innate immune receptors contribute to disease association with microbiota alterations, particularly with the Verrucomicrobia phylum.ImportanceTrem-2 is a mammalian innate immunity receptor involved in development and resolution of tissue damage, namely in the brain and in the liver. Nevertheless, it is not known whether gut microbiota is contributing to these Trem-2 mediated phenotypes. We found that Trem-2 KO mice spontaneously display different gut microbiota composition as compared to wild-type mice, namely with increased abundance of the phylum Verrucomicrobia. Notably these differences do not impact the control of Trem-2 on liver tissue vulnerability to hepatotoxic insults. This work uncouples Trem-2 modulation of gut microbiota and the role of Trem-2 on responses to liver damage. This work brings new insights on role of innate immune receptors on the association of organic and systemic diseases with gut microbiota.

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