Fermented Foods in Medicine: An Evaluation of Their Uses and Effects on the Human Gut Microbiota

ABSTRACT The human microbiota is a key contributor to many aspects of human health and its composition is largely influenced by diet. There is a growing body of scientific evidence to suggest that gut dysbiosis (microbial imbalance of the intestine) is associated with inflammatory and immune-mediated diseases (e.g., inflammatory bowel disease and asthma). Regular consumption of fermented foods (e.g., kimchi, kefir, etc.) may represent a potential avenue to counter the proinflammatory effects of gut dysbiosis. However, an assessment of the available literature in this research area is lacking. Here we provide a critical review of current human intervention studies that analyzed the effect of fermented foods on the composition and/or function of the human gut microbiota. A total of 19 human intervention studies were identified that met this search criteria. In this review, we discuss evidence that consumption of fermented foods may modify the gut microbiota in humans. Further, there is cursory evidence to suggest that gut microbiota compositional changes mediate associations between fermented food consumption and human health outcomes. Although promising, there remains considerable heterogeneity in the human populations targeted in the intervention studies we identified. Larger longitudinal feeding studies with longer follow-up are necessary to confirm and enhance the current data. Further, future studies should consider analyzing microbiota function as a means to elucidate the mechanism linking fermented food consumption with human health. This review highlights methodologic considerations for intervention trials, emphasizing an expanse of research opportunities related to fermented food consumption in humans.

Download Full-text

Colonization Ability and Impact on Human Gut Microbiota of Foodborne Microbes From Traditional or Probiotic-Added Fermented Foods: A Systematic Review

Frontiers in Nutrition ◽

10.3389/fnut.2021.689084 ◽

2021 ◽

Vol 8 ◽

Author(s):

Marianna Roselli ◽

Fausta Natella ◽

Paola Zinno ◽

Barbara Guantario ◽

Raffaella Canali ◽

...

Keyword(s):

Systematic Review ◽

Gut Microbiota ◽

Human Health ◽

Fermented Foods ◽

Human Gut ◽

Human Gut Microbiota ◽

Colonization Ability ◽

Scientific Results ◽

Gut Microorganisms ◽

Study Designs

A large subset of fermented foods act as vehicles of live environmental microbes, which often contribute food quality assets to the overall diet, such as health-associated microbial metabolites. Foodborne microorganisms also carry the potential to interact with the human gut microbiome via the food chain. However, scientific results describing the microbial flow connecting such different microbiomes as well as their impact on human health, are still fragmented. The aim of this systematic review is to provide a knowledge-base about the scientific literature addressing the connection between foodborne and gut microbiomes, as well as to identify gaps where more research is needed to clarify and map gut microorganisms originating from fermented foods, either traditional or added with probiotics, their possible impact on human gut microbiota composition and to which extent foodborne microbes might be able to colonize the gut environment. An additional aim was also to highlight experimental approaches and study designs which could be better standardized to improve comparative analysis of published datasets. Overall, the results presented in this systematic review suggest that a complex interplay between food and gut microbiota is indeed occurring, although the possible mechanisms for this interaction, as well as how it can impact human health, still remain a puzzling picture. Further research employing standardized and trans-disciplinary approaches aimed at understanding how fermented foods can be tailored to positively influence human gut microbiota and, in turn, host health, are therefore of pivotal importance.

Download Full-text

In vitro study of the interaction between human gut microbiota and herbal extracts using willow bark extract as an example

Planta Medica ◽

10.1055/s-0036-1596386 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

EM Pferschy-Wenzig ◽

K Koskinen ◽

C Moissl-Eichinger ◽

R Bauer

Keyword(s):

Gut Microbiota ◽

In Vitro Study ◽

Vitro Study ◽

Bark Extract ◽

Herbal Extracts ◽

Human Gut ◽

Human Gut Microbiota ◽

Willow Bark

Download Full-text

Metabolization of the herbal combination STW-5 by human gut microbiota in vitro

10.1055/s-0037-1608399 ◽

2017 ◽

Author(s):

EM Pferschy-Wenzig ◽

A Roßmann ◽

K Koskinen ◽

H Abdel-Aziz ◽

C Moissl-Eichinger ◽

...

Keyword(s):

Gut Microbiota ◽

Human Gut ◽

Human Gut Microbiota

Download Full-text

Substrate use prioritization by a coculture of five species of gut bacteria fed mixtures of arabinoxylan, xyloglucan, β-glucan, and pectin

10.26686/wgtn.12585620.v1 ◽

2020 ◽

Author(s):

Y Liu ◽

AL Heath ◽

B Galland ◽

N Rehrer ◽

L Drummond ◽

...

Keyword(s):

Gut Microbiota ◽

Dietary Fiber ◽

Plant Cell Wall ◽

Bacterial Species ◽

Short Chain ◽

Emergent Properties ◽

Human Gut ◽

Fermentation Products ◽

Plant Polysaccharides ◽

Human Gut Microbiota

© 2020 American Society for Microbiology. Dietary fiber provides growth substrates for bacterial species that belong to the colonic microbiota of humans. The microbiota degrades and ferments substrates, producing characteristic short-chain fatty acid profiles. Dietary fiber contains plant cell wall-associated polysaccharides (hemicelluloses and pectins) that are chemically diverse in composition and structure. Thus, depending on plant sources, dietary fiber daily presents the microbiota with mixtures of plant polysaccharides of various types and complexity. We studied the extent and preferential order in which mixtures of plant polysaccharides (arabinoxylan, xyloglucan, β-glucan, and pectin) were utilized by a coculture of five bacterial species (Bacteroides ovatus, Bifidobacterium longum subspecies longum, Megasphaera elsdenii, Ruminococcus gnavus, and Veillonella parvula). These species are members of the human gut microbiota and have the biochemical capacity, collectively, to degrade and ferment the polysaccharides and produce short-chain fatty acids (SCFAs). B. ovatus utilized glycans in the order β-glucan, pectin, xyloglucan, and arabinoxylan, whereas B. longum subsp. longum utilization was in the order arabinoxylan, arabinan, pectin, and β-glucan. Propionate, as a proportion of total SCFAs, was augmented when polysaccharide mixtures contained galactan, resulting in greater succinate production by B. ovatus and conversion of succinate to propionate by V. parvula. Overall, we derived a synthetic ecological community that carries out SCFA production by the common pathways used by bacterial species for this purpose. Systems like this might be used to predict changes to the emergent properties of the gut ecosystem when diet is altered, with the aim of beneficially affecting human physiology. This study addresses the question as to how bacterial species, characteristic of the human gut microbiota, collectively utilize mixtures of plant polysaccharides such as are found in dietary fiber. Five bacterial species with the capacity to degrade polymers and/or produce acidic fermentation products detectable in human feces were used in the experiments. The bacteria showed preferential use of certain polysaccharides over others for growth, and this influenced their fermentation output qualitatively. These kinds of studies are essential in developing concepts of how the gut microbial community shares habitat resources, directly and indirectly, when presented with mixtures of polysaccharides that are found in human diets. The concepts are required in planning dietary interventions that might correct imbalances in the functioning of the human microbiota so as to support measures to reduce metabolic conditions such as obesity.

Download Full-text