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.

Physicochemical interaction with faecal bacteria in characterisation of beach water quality, Gulf of Guinea, Ghana

Human activities such as industrial and agricultural waste discharges directly in the coastal areas increasingly contribute to pollution in coastal waters of Western Africa. The study employed physicochemical and faecal analysis to understand water pollution along the coast of Ghana. The physicochemical parameter such as temperature, salinity, electrical conductivity, pH, dissolved oxygen concentration, dissolved oxygen saturation, total dissolved solids, and redox potential) were measured in situ while water samples were collected determination of total suspended solids, nutrients, chlorophyll-a, and faecal bacteria. The abundance of total coliforms (4061.6 ± 4159.14 CFU/100 ml water), Escherichia coli, and Enterococcus spp. varied significantly (p < 0.05) among the beaches. The high amount of faecal bacteria suggest microbial contamination, possible ecosystem, and health risks to water resource users. This baseline study provides evidence of coastal water contamination to improve beach water quality standards to ensure safe environmental health.

Cyclin M2 (CNNM2) knockout mice show mild hypomagnesaemia and developmental defects

Patients with mutations in Cyclin M2 (CNNM2) suffer from hypomagnesaemia, seizures, and intellectual disability. Although the molecular function of CNNM2 is under debate, the protein is considered essential for renal Mg2+ reabsorption. Here, we used a Cnnm2 knock out mouse model, generated by CRISPR/Cas9 technology, to assess the role of CNNM2 in Mg2+ homeostasis. Breeding Cnnm2+/− mice resulted in a Mendelian distribution at embryonic day 18. Nevertheless, only four Cnnm2−/− pups were born alive. The Cnnm2−/− pups had a significantly lower serum Mg2+ concentration compared to wildtype littermates. Subsequently, adult Cnnm2+/− mice were fed with low, control, or high Mg2+ diets for two weeks. Adult Cnnm2+/− mice showed mild hypomagnesaemia compared to Cnnm2+/+ mice and increased serum Ca2+ levels, independent of dietary Mg2+ intake. Faecal analysis displayed increased Mg2+ and Ca2+ excretion in the Cnnm2+/− mice. Transcriptional profiling of Trpm6, Trpm7, and Slc41a1 in kidneys and colon did not reveal effects based on genotype. Microcomputed tomography analysis of the femurs demonstrated equal bone morphology and density. In conclusion, CNNM2 is vital for embryonic development and Mg2+ homeostasis. Our data suggest a previously undescribed role of CNNM2 in the intestine, which may contribute to the Mg2+ deficiency in mice and patients.

Gut Microbiota Hypolipidemic Modulating Role in Diabetic Rats Fed with Fermented Parkia biglobosa (Fabaceae) Seeds

Background: Modulation and balancing of host gut microbiota by probiotics has been documented by several literature. Prebiotic diets such as locust beans have been known to encourage the occurrence of these beneficial microorganisms in the host gut. Objectives: To study the modulating role of gut microbiota in the hypolipidemic effect of fermented locust beans on diabetic Albino Wister rats as animal models. Methodology: Albino rats (Wistar strain), averagely weighing 125g were successfully induced with alloxan. Thereafter this induction, anti-diabetic treatment was carried out on various groups of rats by feeding them ad-libitum with a diet of milled fermented and unfermented Parkia biglobosa seeds, respectively. Results: After three weeks of treatment, it was observed that fermented locust beans caused a significant reduction (p ≤ 0.05) in glucose, total triglycerides, total cholesterol and LDL, while the HDL levels were significantly elevated (p ≤ 0.05). Results of faecal analysis showed that the fermented locust beans modulated the gut microbiota through the occurrence of probiotic bacteria, Bacillus subtilis in the gut and faeces of the rats. Conclusion: This study support that fermented locust beans is a prebiotic diet that encourages the growth of Bacillus subtilis in the gut of animals and is associated with hypolipidemic activities which alleviate diabetes as portrayed in these rat models.

The effects of two calcium supplementation regimens on growth and health traits of juvenile mountain chicken frogs (Leptodactylus fallax)

The mountain chicken frog (Leptodactylus fallax) is among the 42 % of amphibians threatened with extinction and is dependent upon ex situ populations to recover in the wild. Amphibian captive husbandry is not fully understood and empirical data are required to optimise protocols for each species in captivity. Calcium metabolism and homeostasis are areas of importance in captive husbandry research and have been identified as a challenge in maintaining ex situ populations of L. fallax. We trialled two frequencies (twice and seven times weekly) of calcium supplementation via dusting of feeder insects in two groups of L. fallax juveniles and measured growth and health effects through morphometrics, radiography, ultrasonography and blood and faecal analysis over 167 days, followed by a further 230 days of monitoring on an intermediate diet informed by the initial dataset. We showed that supplementation treatment did not affect growth or health status as measured through blood analysis, radiography and ultrasonography. More frequent supplementation resulted in significantly more radiopaque endolymphatic sacs and broader skulls. Frogs fed more calcium excreted twice as much calcium in their faeces. The intermediate diet resulted in previously lower supplementation frogs approximating the higher supplementation frogs in morphometrics and calcium stores. Comparison with radiographic data from wild frogs showed that both treatments may still have had narrower skulls than wild animals, but mismatching age class may limit this comparison. Our data may be used to inform dietary supplementation of captive L. fallax as well as other amphibians.

Notes on the diet and foraging habits of the Giant Barred Frog Mixophyes iteratus

Australian anurans generally display little prey specialisation. Most data available of frog diet is limited to stomach content and faecal analysis with few direct observations of prey capture. Limited information is available on the diet of adult Giant Barred Frogs Mixophyes iteratus. In this paper I report on several observations of M. iteratus feeding on a variety of prey from various taxa. These observations suggest that M. iteratus are opportunistic, ambush predators with a broad diet. Their morphology and hunting behaviour align with existing models of amphibian foraging patterns.

Prevalence of gastrointestinal parasites in captive animals in selected private zoos in south-west Nigeria

This study was carried out to determine the gastrointestinal parasite profile of captive animals kept in three private zoological gardens (Olusegun Obasanjo Presidential Library (OOPL) Wildlife Park, Q-BRAT Zoos and Gardens, OMU Resort) in south-west Nigeria. Animals were screened for gastrointestinal parasites via faecal analysis using standard coprological techniques. A total of 104 faecal samples were collected from forty-three animal species across the three zoos. Faecal samples examination revealed an overall parasite prevalence of 41.37%. The prevalence in OOPL was 35.29%, 62.5% in Q-BRAT and 40.54% in OMU. Gastrointestinal helminths identified were hookworm, Ascaris sp, Clonorchis sp, Enterobius sp, Trichuris sp and Dipylidium sp, while Entamoeba sp, Giardia sp and coccidian parasites were the only protozoans present. Hookworm and Ascaris sp had the highest prevalence of 39.53% and 18.60% respectively. Prevalence across five categories of captive animals (aves, herbivores, carnivores, primates and reptiles) showed that primates and herbivores had the highest prevalence rates (54.55% and 43.75% respectively). Coccidian parasites had the highest intensity in birds at OOPL. This study shows the presence of parasites of zoonotic importance (Entamoeba sp, Hookworm, Ascaris sp, Giardia sp Enterobius sp and Trichuris sp) among screened animals. The result of this survey calls for the improvement of husbandry practices, continuous parasite surveillance and therapeutic practices in the zoos in order to prevent a breakdown of animal and public health. Keywords: Gastrointestinal parasites; captive animals; zoological gardens, zoonosis; public health; south-west Nigeria.