Phase-variable bacteria simultaneously express multiple capsules

Capsular polysaccharides (CPSs) protect bacteria from host and environmental factors. Many bacteria can express different CPSs and these CPSs are phase variable. For example, Bacteroides thetaiotaomicron (B. theta) is a prominent member of the human gut microbiome and expresses eight different capsular polysaccharides. Bacteria, including B. theta, have been shown to change their CPSs to adapt to various niches such as immune, bacteriophage, and antibiotic perturbations. However, there are limited tools to study CPSs and fundamental questions regarding phase variance, including if gut bacteria can express more than one capsule at the same time, remain unanswered. To better understand the roles of different CPSs, we generated a B. theta CPS1-specific antibody and a flow cytometry assay to detect CPS expression in individual bacteria in the gut microbiota. Using these novel tools, we report for the first time that bacteria can simultaneously express multiple CPSs. We also observed that nutrients such as glucose and salts had no effect on CPS expression. The ability to express multiple CPSs at the same time may provide bacteria with an adaptive advantage to thrive amid changing host and environmental conditions, especially in the intestine.

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Relationship between Nutrient Intake and Human Gut Microbiota in Monozygotic Twins

Medicina ◽

10.3390/medicina57030275 ◽

2021 ◽

Vol 57 (3) ◽

pp. 275

Author(s):

Natsuko Matsumoto ◽

Jonguk Park ◽

Rie Tomizawa ◽

Hitoshi Kawashima ◽

Koji Hosomi ◽

...

Keyword(s):

Individual Differences ◽

Environmental Factors ◽

Gut Microbiota ◽

Human Health ◽

Negative Correlation ◽

Nutrient Intake ◽

Monozygotic Twins ◽

Human Gut ◽

Positive Correlation ◽

Human Gut Microbiota

Background and Objectives: The gut microbiota is associated with human health and dietary nutrition. Various studies have been reported in this regard, but it is difficult to clearly analyze human gut microbiota as individual differences are significant. The causes of these individual differences in intestinal microflora are genetic and/or environmental. In this study, we focused on differences between identical twins in Japan to clarify the effects of nutrients consumed on the entire gut microbiome, while excluding genetic differences. Materials and Methods: We selected healthy Japanese monozygotic twins for the study and confirmed their zygosity by matching 15 short tandem repeat loci. Their fecal samples were subjected to 16S rRNA sequencing and bioinformatics analyses to identify and compare the fluctuations in intestinal bacteria. Results: We identified 12 genera sensitive to environmental factors, and found that Lactobacillus was relatively unaffected by environmental factors. Moreover, we identified protein, fat, and some nutrient intake that can affect 12 genera, which have been identified to be more sensitive to environmental factors. Among the 12 genera, Bacteroides had a positive correlation with retinol equivalent intake (rs = 0.38), Lachnospira had a significantly negative correlation with protein, sodium, iron, vitamin D, vitamin B6, and vitamin B12 intake (rs = −0.38, −0.41, −0.39, −0.63, −0.42, −0.49, respectively), Lachnospiraceae ND3007 group had a positive correlation with fat intake (rs = 0.39), and Lachnospiraceae UCG-008 group had a negative correlation with the saturated fatty acid intake (rs = −0.45). Conclusions: Our study is the first to focus on the relationship between human gut microbiota and nutrient intake using samples from Japanese twins to exclude the effects of genetic factors. These findings will broaden our understanding of the more intuitive relationship between nutrient intake and the gut microbiota and can be a useful basis for finding useful biomarkers that contribute to human health.

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Precision modification of the human gut microbiota targeting surface-associated proteins

Scientific Reports ◽

10.1038/s41598-020-80187-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Raquel Marcos-Fernández ◽

Lorena Ruiz ◽

Aitor Blanco-Míguez ◽

Abelardo Margolles ◽

Borja Sánchez

Keyword(s):

Flow Cytometry ◽

Gut Microbiota ◽

Magnetic Particles ◽

Protein A ◽

Single Species ◽

Single Step ◽

Specific Cell ◽

Human Gut ◽

Human Gut Microbiota ◽

Associated Proteins

AbstractThis work describes a new procedure that allows the targeted modification of the human gut microbiota by using antibodies raised against bacterial surface-associated proteins specific to the microorganism of interest. To this end, a polyclonal antibody recognising the surface-associated protein Surface Layer Protein A of Lactobacillus acidophilus DSM20079T was developed. By conjugating this antibody with fluorescent probes and magnetic particles, we were able to specifically identify this bacterium both in a synthetic, and in real gut microbiotas by means of a flow cytometry approach. Further, we demonstrated the applicability of this antibody to deplete complex human gut microbiotas from L. acidophilus in a single step. L. acidophilus was found to interact with other bacteria both in synthetic and in real microbiotas, as reflected by its concomitant depletion together with other species. Further optimization of the procedure including a trypsin step enabled to achieve the selective and complete isolation of this species. Depleting a single species from a gut microbiota, using antibodies recognizing specific cell surface elements of the target organism, will open up novel ways to tackle research on the specific immunomodulatory and metabolic contributions of a bacterium of interest in the context of a complex human gut microbiota, including the investigation into therapeutic applications by adding/depleting a key bacterium. This represents the first work in which an antibody/flow-cytometry based application enabled the targeted edition of human gut microbiotas, and represents the basis for the design of precision microbiome-based therapies.

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Feeding with Sustainably Sourdough Bread Has the Potential to Promote the Healthy Microbiota Metabolism at the Colon Level

Microbiology Spectrum ◽

10.1128/spectrum.00494-21 ◽

2021 ◽

Author(s):

Alessio Da Ros ◽

Andrea Polo ◽

Carlo Giuseppe Rizzello ◽

Marta Acin-Albiac ◽

Marco Montemurro ◽

...

Keyword(s):

Environmental Factors ◽

Gut Microbiota ◽

Dietary Habits ◽

Human Gut ◽

Human Gut Microbiota ◽

Sourdough Bread ◽

Host Physiology

Knowledge on environmental factors, which may compose the gut microbiota, and drive the host physiology and health is of paramount importance. Human dietary habits and food compositions are pivotal drivers to assembly the human gut microbiota, but, inevitably, unmapped for many diet components, which are poorly investigated individually.

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Gut health: predictive biomarkers for preventive medicine and development of functional foods

British Journal Of Nutrition ◽

10.1017/s0007114509993400 ◽

2010 ◽

Vol 103 (10) ◽

pp. 1539-1544 ◽

Cited By ~ 17

Author(s):

Raish Oozeer ◽

Maria Rescigno ◽

R. Paul Ross ◽

Jan Knol ◽

Michael Blaut ◽

...

Keyword(s):

Gut Microbiota ◽

Predictive Biomarkers ◽

Gut Health ◽

Human Gut ◽

Observation Study ◽

Industry Collaboration ◽

Health And Disease ◽

Micro Organisms ◽

First Time

There is an urgent need to develop and validate a series of biomarkers, which accurately measure and inform on how the human gut microbiota can affect human health. The human gut hosts a complex community of micro-organisms, with unique features in each individual. The functional role of this gut microbiota in health and disease is increasingly evident, but poorly understood. Comprehension of this ecosystem implies a significant challenge in the elucidation of interactions between all of its components, but promises a paradigm shift in preventive nutrition and medicine. ‘Omics’ technologies for the first time offer tools of sufficient subtlety to tackle this challenge. However, these techniques must be allied with traditional skills of the microbial physiologist, which are in danger of being lost. Targeting these efforts at the identification of biomarkers associated with gut health will require access to a ‘biobank’ from a pan-European or worldwide observation study, which would include samples taken with appropriate frequency from healthy individuals of different ages. This offers a pragmatic opportunity for a unique food and pharmaceutical industry collaboration.

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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

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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

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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.

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