Vegan Diet and the Gut Microbiota Composition in Healthy Adults

The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut microbiota can be considered a virtual organ of the body, playing a pivotal role in health maintenance. Dietary habits contribute to gut microbiota composition, and evidence from observational and intervention studies suggest that vegan diets may promote health, potentially through affecting the diverse ecosystem of beneficial bacteria in the gut. A systematic literature search was conducted on PubMed and Scopus to identify studies investigating the microbiota composition in vegans. Vegans are defined as people excluding food products that are derived from animals from their diet. Nine observational studies were identified. The main outcome of the systematic review was an increase in Bacteroidetes on the phylum level and a higher abundance of Prevotella on the genus level. In conclusion, the present systematic literature review highlighted some benefits of a vegan diet but also demonstrated the complexity of evaluating results from gut microbiota research. The available evidence only consisted of cross-sectional studies, therefore suggesting the need for well-designed randomised controlled trials. Furthermore, the quality assessment of the studies included in the review suggested a lack of standardised and validated methods for participant selection as well as for faecal sampling and faecal analysis.

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Sex differences in the phylum‐level human gut microbiota composition

BMC Microbiology ◽

10.1186/s12866-021-02198-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Alexander Koliada ◽

Vladislav Moseiko ◽

Mariana Romanenko ◽

Oleh Lushchak ◽

Nadiia Kryzhanovska ◽

...

Keyword(s):

Sex Differences ◽

Gut Microbiota ◽

Age Groups ◽

Microbiota Composition ◽

Human Gut ◽

Cross Sectional ◽

Total N ◽

Human Gut Microbiota ◽

Gut Microbiota Composition

Abstract Background Evidence was previously provided for sex-related differences in the human gut microbiota composition, and sex-specific discrepancy in hormonal profiles was proposed as a main determinant of these differences. On the basis of these findings, the assumption was made on the role of microbiota in the sexual dimorphism of human diseases. To date, sex differences in fecal microbiota were demonstrated primarily at lower taxonomic levels, whereas phylum-level differences between sexes were reported in few studies only. In the present population-based cross-sectional research, sex differences in the phylum-level human gut microbiota composition were identified in a large (total n = 2301) sample of relatively healthy individuals from Ukraine. Results Relative abundances of Firmicutes and Actinobacteria, as determined by qRT-PCR, were found to be significantly increased, while that of Bacteroidetes was significantly decreased in females compared to males. The Firmicutes to Bacteroidetes (F/B) ratio was significantly increased in females compared to males. Females had 31 % higher odds of having F/B ratio more than 1 than males. This trend was evident in all age groups. The difference between sexes was even more pronounced in the elder individuals (50+): in this age group, female participants had 56 % higher odds of having F/B ratio > 1 than the male ones. Conclusions In conclusion, sex-specific differences in the phylum-level intestinal microbiota composition were observed in the Ukraine population. The F/B ratio was significantly increased in females compared to males. Further investigation is needed to draw strong conclusions regarding the mechanistic basis for sex-specific differences in the gut microbiota composition and regarding the role of these differences in the initiation and progression of human chronic diseases.

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Ketonuria Is Associated with Changes to the Abundance of Roseburia in the Gut Microbiota of Overweight and Obese Women at 16 Weeks Gestation: A Cross-Sectional Observational Study

Nutrients ◽

10.3390/nu11081836 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1836 ◽

Cited By ~ 2

Author(s):

Helen Robinson ◽

Helen Barrett ◽

Luisa Gomez-Arango ◽

H. David McIntyre ◽

Leonie Callaway ◽

...

Keyword(s):

Gut Microbiota ◽

Pregnant Women ◽

Clustering Analysis ◽

Alpha Diversity ◽

Microbiota Composition ◽

Obese Women ◽

Cross Sectional ◽

Low Carbohydrate ◽

Rrna Sequencing ◽

Gut Microbiota Composition

The gut microbiome in pregnancy has been associated with various maternal metabolic and hormonal markers involved in glucose metabolism. Maternal ketones are of particular interest due to the rise in popularity of low-carbohydrate diets. We assessed for differences in the composition of the gut microbiota in pregnant women with and without ketonuria at 16 weeks gestation. Fecal samples were obtained from 11 women with fasting ketonuria and 11 matched controls. The samples were analyzed to assess for differences in gut microbiota composition by 16S rRNA sequencing. Supervised hierarchical clustering analysis showed significantly different beta-diversity between women with and without ketonuria, but no difference in the alpha-diversity. Group comparisons and network analysis showed that ketonuria was associated with an increased abundance of the butyrate-producing genus Roseburia. The bacteria that contributed the most to the differences in the composition of the gut microbiota included Roseburia, Methanobrevibacter, Uncl. RF39, and Dialister in women with ketonuria and Eggerthella, Phascolarctobacterium, Butyricimonas, and Uncl. Coriobacteriaceae in women without ketonuria. This study found that the genus Roseburia is more abundant in the gut microbiota of pregnant women with ketonuria. Roseburia is a butyrate producing bacterium and may increase serum ketone levels.

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Seasonal variation in gut microbiota composition: cross-sectional evidence from Ukrainian population

BMC Microbiology ◽

10.1186/s12866-020-01786-8 ◽

2020 ◽

Vol 20 (1) ◽

Cited By ~ 3

Author(s):

Alexander Koliada ◽

Vladyslav Moseiko ◽

Mariana Romanenko ◽

Liubov Piven ◽

Oleh Lushchak ◽

...

Keyword(s):

Seasonal Variation ◽

Gut Microbiota ◽

Microbiota Composition ◽

Cross Sectional ◽

Gut Microbiota Composition

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Gut Microbiota Composition across Normal Range Prostate-Specific Antigen Levels

Journal of Personalized Medicine ◽

10.3390/jpm11121381 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1381

Author(s):

Han-Na Kim ◽

Jae-Heon Kim ◽

Yoosoo Chang ◽

Dongmin Yang ◽

Hyung-Lae Kim ◽

...

Keyword(s):

Gut Microbiota ◽

Prostate Specific Antigen ◽

Specific Antigen ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Microbiota Composition ◽

Sequencing Data ◽

Normal Range ◽

Cross Sectional ◽

Gut Microbiota Composition

Animal studies have shown the interaction between androgens and the gut microbiome directly and indirectly; however, limited evidence from human studies is available. To evaluate the association between prostate-specific antigen (PSA) levels within the normal range, reflective of androgen receptor activity, and the gut microbiota composition, a cross-sectional analysis was performed in 759 Korean men aged between 25 and 78 years with normal PSA levels of ≤4.0 ng/mL. We evaluated the biodiversity of gut microbiota as well as the taxonomic and functional signatures associated with PSA levels using 16S rRNA gene sequencing data. PSA levels within the normal range were categorized into three groups: lowest quartile (G1), interquartile range (G2, reference), and highest quartile (G3). The G3 group had higher microbial richness than the G2 group, although it was dominated by a few bacteria. An increase in Escherichia/Shigella abundance and a reduction in Megamonas abundance in the G3 group were also detected. A U-shaped relationship was observed between the three groups across most analyses, including biodiversity, taxonomic composition, and inferred pathways in the gut microbiota. This study showed different microbiota patterns across PSA levels within the normal range. Further studies are required to elucidate the role of microbiota in regulating PSA levels.

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P841 Evaluation of gut microbiota composition in NAFLD with UC pancolitis in clinical remission: a pilot study

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjz203.969 ◽

2020 ◽

Vol 14 (Supplement_1) ◽

pp. S650-S651

Author(s):

S Cocciolillo ◽

G De Palma ◽

T Chen ◽

M P Ghali ◽

M Deschenes ◽

...

Keyword(s):

Liver Disease ◽

Pilot Study ◽

Gut Microbiota ◽

Clinical Remission ◽

Transient Elastography ◽

Rrna Gene ◽

Microbiota Composition ◽

Cross Sectional ◽

Alcoholic Fatty Liver ◽

Gut Microbiota Composition

Abstract Background Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver disease in Western countries and is a frequently reported comorbidity in inflammatory bowel disease (IBD). A complex interaction among polygenic predisposition, IBD-specific risk factors, microbiome, multiple environmental and patients’ factors could explain the development of NAFLD in IBD. Gut dysbiosis is increasingly recognised as an important player in NAFLD, as well as in IBD pathogenesis. So far, no study has examined the gut microbiota composition in IBD patients with NAFLD. We aimed to characterise faecal microbiota according to NAFLD status in a pilot cohort of ulcerative colitis (UC) pancolitis in clinical remission. Methods This was a cross-sectional pilot study using transient elastography (TE) with controlled attenuation parameter (CAP) to diagnose NAFLD in UC pancolitis patients in clinical remission, defined as partial Mayo score ≤1. NAFLD was diagnosed non-invasively as CAP ≥248 dB/m. Exclusion criteria included: use of corticosteroids in the last year and antibiotics or probiotics/prebiotics in the last 2 months prior to inclusion; significant alcohol intake (AUDIT-C <5); hepatitis B or C infection. Stool samples were collected within 12 h from TE with CAP evaluation. Gut microbiota composition was analysed by 16S rRNA gene sequencing with Illumina technique. Statistical analysis by NAFLD status was performed using Fisher’s exact or Mann–Whitney’s test as appropriate. Results A total of 11 UC pancolitis patients in clinical remission were included (mean age 53 years, 36.4% male, time since IBD diagnosis 16 years). NAFLD was diagnosed in 7 cases (63.6%, mean CAP 291 dB/m). Patients with pancolitis and NAFLD had higher BMI (mean 31 vs. 22 kg/m2, p = 0.006) as well as waist circumference (mean 100 vs. 81 cm, p = 0.006) compared with those without NAFLD, but no other differences in demographic, clinical or pharmacological parameters were found between pancolitis with or without NAFLD. Patients with pancolitis and NAFLD clustered separately from those without NAFLD, when computing Bray Curtis dissimilarities (tested with Adonis, p = 0.006). In addition, patients with pancolitis and NAFLD presented with decreased bacterial richness (p = 0.017) but not diversity. This was accompanied by a significant increase of Bacteroides spp. relative abundance in faecal samples of patients with pancolitis and NAFLD (q = 0.017). Conclusion This pilot study demonstrates, for the first time, that, in UC pancolitis patients, NAFLD associates with altered gut microbiota composition. Further studies are needed to understand the exact role of gut microbiota in UC pancolitis with NAFLD and to evaluate the use of microbiota-directed approaches for the treatment of NAFLD in these patients.

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Physical activity and gut microbiota: a cross-sectional study

European Journal of Public Health ◽

10.1093/eurpub/ckaa166.413 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

F Gallè ◽

F Valeriani ◽

M Antinozzi ◽

R Liguori ◽

G Gianfranceschi ◽

...

Keyword(s):

Physical Activity ◽

Gut Microbiota ◽

Amplicon Sequencing ◽

Cross Sectional Study ◽

Microbiota Composition ◽

Sectional Study ◽

Microbial Composition ◽

Cross Sectional ◽

Bacterial Phyla ◽

Gut Microbiota Composition

Abstract Background The composition of gut microbiota, and in particular the intestinal abundance of the two main bacterial phyla of Firmicutes and Bacteroidetes, are associated with human health and diseases and may be conditioned by host and environmental factors such as age, gender and diet. The role of Physical Activity (PA) in determining gut microbiota composition has not been yet completely clarified. A cross-sectional study involving undergraduates from two Italian cities is ongoing to explore this relationship. Methods Students were invited to provide a fecal sample and to complete the International Physical Activity Questionnaire (IPAQ) in order to define their habitual PA level (inactive, minimally active, health enhancing physical activity -HEPA- active). Demographic and anthropometric information were also collected. DNA from fecal samples was analyzed through the 16S amplicon sequencing. Microbial composition and variability of the samples were evaluated on the light of participants' PA levels. Results A total of 153 students (47.7% males, mean age 22.4±2.9, mean BMI 22.3±2.7) participated to the study so far. Firmicutes and Bacteroidetes were the main represented phyla. An increase in Firmicutes (58.3±16 to 61.4±13.3, p = 0.68) and a reduction in Bacteroidetes (32.6±14.8 to 30.3±11.4, p = 0.51) have been registered with the increase of PA level. A higher variability (expressed as Shannon α-index) has been detected in minimally active (3.39±0.03) and HEPA-active (3.41±0) individuals respect to inactive subjects (3.35±0.07) (p = 0.05). Conclusions Even if they are not significant, these preliminary results suggest a relationship between PA levels and gut microbiota composition. An active lifestyle seems to be associated with a greater microbial diversity in the gut. Further researches are needed to explain these findings. Key messages Physical activity seems to be associated with gut microbiota composition. A greater variability in gut microbiota was found in active people.

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Obesity and mental health improvement following nutritional education focusing on gut microbiota composition in Japanese women: a randomised controlled trial

European Journal of Nutrition ◽

10.1007/s00394-018-1873-0 ◽

2018 ◽

Vol 58 (8) ◽

pp. 3291-3302 ◽

Cited By ~ 5

Author(s):

Mayu Uemura ◽

Fumikazu Hayashi ◽

Ken Ishioka ◽

Kunio Ihara ◽

Kazushi Yasuda ◽

...

Keyword(s):

Mental Health ◽

Randomised Controlled Trial ◽

Gut Microbiota ◽

Controlled Trial ◽

Japanese Women ◽

Health Improvement ◽

Microbiota Composition ◽

Nutritional Education ◽

Randomised Controlled ◽

Gut Microbiota Composition

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The influence of dietary compounds on gut microbiota

Slovenian Medical Journal ◽

10.6016/zdravvestn.3005 ◽

2021 ◽

pp. 1-15

Author(s):

Maja Šikić Pogačar ◽

Dušanka Mičetić-Turk

Keyword(s):

Gut Microbiota ◽

Energy Homeostasis ◽

High Throughput Sequencing ◽

Dietary Habits ◽

Lifestyle Changes ◽

Bioactive Metabolites ◽

Microbiota Composition ◽

Interindividual Variations ◽

Mass Spectrometry Identification ◽

Gut Microbiota Composition

The gut microbiota is a complex community composed of trillions of microbes that adapts to its host over the lifetime. Recently, the advances of the methods of high-throughput sequencing have allowed the identification of microbial species in a stool sample, and mass spectrometry identification of their metabolites, both of which together have enabled much of the relevant research in the field. It has became evident that gut microbiota plays an important role in human health and influences the risk of developing many chronic diseases, including obesity, inflammatory bowel disease, type 2 diabetes, cardiovascular disease, and cancer. The diverse ecosystem of the gut includes bacteria, viruses, phages, yeasts, archaea, fungi and protozoa. They are responsible for the production of bioactive metabolites, regulation of immune function, energy homeostasis and protection against pathogens. The mentioned functions are dependent on the diversity and abundance of the microbiota which is the reflection of the dietary habits and genetics of the host among other factors. As such, gut microbiota has significant interindividual variations. Diet and lifestyle changes present important determinants in microbiota shaping. The use of antibiotics, different sanitation measures, consumption of processed food and different diets are also reflected in the shifts of gut microbiota composition. Some of the dramatic dietary alterations can cause changes in gut microbiota composition already within 24 h and some of these changes may be difficult to reverse. Through modulation of gut microbiota composition, diet could offer a potential to manage the risk of developing disease and at the same time improving the quality of life and longevity. In this review we look at the role of diet, and specific dietary components, namely carbohydrates, proteins, fats and polyphenols on gut microbiota composition.

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The effects of physical activity on human gut microbiota composition: a systematic review

European Journal of Public Health ◽

10.1093/eurpub/ckaa166.437 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

B Dorelli ◽

M Iachini ◽

M Zaccarin ◽

J Preziosi Standoli ◽

F Galle ◽

...

Keyword(s):

Physical Activity ◽

Systematic Review ◽

Gut Microbiota ◽

Moderate Intensity ◽

Microbiota Composition ◽

Human Gut ◽

Cross Sectional ◽

Human Gut Microbiota ◽

Cross Sectional Studies ◽

Gut Microbiota Composition

Abstract Background Gut microbiota development and composition can be influenced by an existing dynamic balance between host physiology and lifestyle. This systematic review aims to assess the impact of physical activity on human gut microbiota. Methods PubMed, Scopus and Web of Science were searched until May 2019. Full-text in English were recruited if focused on gut microbiota in healthy athletes or active people, without age or gender restrictions, collected on faecal samples and analysed with genome sequencing of rRNA 16S. All types of study design were included as long as they performed a comparison with a sedentary control group. No specific time frame for the publication date was applied. Quality assessment was performed using the JBI Critical Appraisal Checklist for Analytical Cross Sectional Studies (2017) and Cochrane Risk of Bias Tool for Randomized Controlled Trials. Results The analysis yielded 7/985 articles: five cross-sectional studies and two clinical trials, published from 2014 to 2019. The overall methodological assessment was of fair quality. Types of exercise included in the studies were: rugby, running, aerobic exercise, bodybuilding. More in detail, regarding the exercise load, some studies were conducted on elite professional athletes, such as rugby players, marathon runners or bodybuilders, with rigorous training, while other studies included a few weeks of aerobic and resistance training at a moderate intensity. Shannon diversity index increased in three studies. Concerning phyla, Firmicutes were increased in five studies and three studies described a significant decrease in Bacteroides. Conclusions This systematic review confirms the direct correlation between microbiota composition and physical activity, but further studies are needed to establish the possible presence of a causal link between the two factors. Key messages Exercise can play an important role as an environmental factor in determining gut microbiota composition. Further studies are needed to gain robust evidence of physical activity influence on gut microbiota variability.

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