Recent data suggest that the human body is not such a neatly self-sufficient island after all. It is more like a super-complex ecosystem containing trillions of bacteria and other microorganisms that ...inhabit all our surfaces; skin, mouth, sexual organs, and specially intestines. It has recently become evident that such microbiota, specifically within the gut, can greatly influence many physiological parameters, including cognitive functions, such as learning, memory and decision making processes. Human microbiota is a diverse and dynamic ecosystem, which has evolved in a mutualistic relationship with its host. Ontogenetically, it is vertically inoculated from the mother during birth, established during the first year of life and during lifespan, horizontally transferred among relatives, mates or close community members. This micro-ecosystem serves the host by protecting it against pathogens, metabolizing complex lipids and polysaccharides that otherwise would be inaccessible nutrients, neutralizing drugs and carcinogens, modulating intestinal motility, and making visceral perception possible. It is now evident that the bidirectional signaling between the gastrointestinal tract and the brain, mainly through the vagus nerve, the so called "microbiota-gut-vagus-brain axis," is vital for maintaining homeostasis and it may be also involved in the etiology of several metabolic and mental dysfunctions/disorders. Here we review evidence on the ability of the gut microbiota to communicate with the brain and thus modulate behavior, and also elaborate on the ethological and cultural strategies of human and non-human primates to select, transfer and eliminate microorganisms for selecting the commensal profile.
Gut microbiota development in formula‐fed and breast‐fed infants is known to differ. This could relate to the usage of unmodified vegetable oil instead of mammalian fat in infant formula (IF), ...causing the enhanced formation of the poorly soluble soap calcium palmitate (CP) in the infant's gut. Here we investigate in vitro the possible influence of CP on the infant gut bacteria. The growth of several bacterial species dominant in the infant's gut was analyzed by culturing in media with CP. Faecalibacterium prausnitzii as a sensitive representative was analyzed in detail by scanning transmission electron microscopy, membrane staining, gas chromatography, and microbial fuel cell experiments. Of all bacteria tested, the growth of several bifidobacteria and F. prausnitzii was reduced at 0.01 mg/ml CP, Bifidobacterium infantis stopped growing completely. CP reduced the cell envelope thickness of F. prausnitzii, disturbed the cell membrane fatty acids and function of membrane proteins involved in electron transport. CP inhibited the growth of bifidobacteria and faecalibacteria. This suggests that modification of fat in IF may benefit the development of the gut microbiota in formula‐fed infants by supporting the colonization of important beneficial bacteria in early life. Future clinical studies are needed to confirm this.
The use of unmodified vegetable oil instead of mammalian fat in infant formula causes the enhanced formation of the poorly soluble soap calcium palmitate in the infant's gut. This study shows that calcium palmitate inhibits bacterial growth, reduces the bacterial cell envelope thickness, and disturbs the function of membrane proteins involved in electron transport.
Intestinal epithelial cells produce interleukin-18 (IL-18), a key factor in promoting epithelial barrier integrity. Here, we analyzed the potential role of gut bacteria and the hypoxia-inducible ...factor 1α (HIF1α) pathway in regulating mucosal
expression in inflammatory bowel disease (IBD).
Mucosal samples from patients with IBD (
= 760) were analyzed for bacterial composition,
levels and HIF1α pathway activation. Wild-type Caco-2 and CRISPR/Cas9-engineered Caco-2-
-null cells were cocultured with
in a "Human oxygen-Bacteria anaerobic"
system and analyzed by RNA sequencing.
Mucosal
mRNA levels correlated positively with the abundance of mucosal-associated butyrate-producing bacteria, in particular
, and with HIF1α pathway activation in patients with IBD. HIF1α-mediated expression of
, either by a pharmacological agonist (dimethyloxallyl glycine) or
, was abrogated in Caco-2-
-null cells.
Butyrate-producing gut bacteria like
regulate mucosal
expression in a HIF1α-dependent manner that may aid in mucosal healing in IBD.
Biodegradable chelant (S,S)–N,N′-ethylenediaminedisuccinic acid (EDDS) has the more advantages of enhanced metal mobility, rapid degradation, environmental friendliness, and ammonium release. ...However, the risk of metal and/or nitrate residues and leaching within EDDS biodegradation remains as the bottleneck for the widespread application of EDDS-induced phytoremediation. This study aims to explore if the inoculation of plant growth-promoting rhizobacteria (PGPRs) can eliminate the risk associated with the short-term application of EDDS by investigating Cu phytoextraction and soil nitrate content. Results showed that EDDS application significantly increased the copper (Cu) concentration in shoots, soil total Cu, NH4+-N and NO3−-N content, but decreased plant biomass. The inoculation of PGPRs in the soil showed a strong ability to increase plant biomass, Cu phytoextraction and soil NH4+-N content, and decrease soil Cu and NO3−-N content. Moreover, bacterial dominant taxa were found to be the largest contributors to soil NH4+-N and NO3−-N variation, and the abundance of denitrifying bacteria (Bacteroidetes and Stenotrophomonas) decreased in the treatment with PGPRs. The risk of residual Cu and nitrate leaching was reduced by the inoculation of PGPRs without significantly changing the stability of the bacterial community. These new findings indicate that the exogenous application of beneficial rhizobacteria can provide an effective strategy to reduce the risk in metal-contaminated soils of chelant-assisted phytoextraction.
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•Short-term addition of EDDS increased Cu uptake but inhibited plant growth.•The leaching risk of Cu and/or nitrate was exposed in the EDDS biodegradation.•Soil Cu and NO3−-N concentrations were reduced in the presence of PGPRs.•Bacterial dominant taxa were the main contributors to NO3−-N variation.•Chelant-PGPRs system minimized environmental risks with enhanced phytoextraction.
The possibility that microbiota mediates social behaviour and the implications of such relationship, is still a relatively recent field of research that starts to attract the interest of the ...scientific community. The present review compiles studies suggesting that microbiota is homogenized between different individuals through social interactions, and that, in turn, it may be differentiated as a consequence of social isolation or social exclusion. Therefore, that the study of such possibilities suggests its utility as a novel index of the dynamics of social inclusion and exclusion. One useful in evaluating whether subjects belong to specific social groups or not. We consider that these possibilities should motivate relevant empirical studies regarding the link between the homogenization of microbiota, social inclusion and exclusion, a useful effort from a diversity of research fields.
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