Short-chain fatty acids profile in patients with SARS-CoV-2: A case-control study.

Background and Aims: SARS-CoV-2, as a new pandemic disease, affected the world. Short-chain fatty acids (SCFAs) such as acetic, propionic, and butyric acids are the main metabolites of human gut microbiota. The positive effects of SCFAs have been shown in infections caused by respiratory syncytial virus, adenovirus, influenza, and rhinovirus. Therefore, this study aimed to evaluate the concentration of SCFAs in patients with SARS-CoV-2 compared with the healthy group. Methods: This research was designed based on a case and control study. Twenty healthy individuals as the control group and 20 persons admitted to the hospital with a positive test of coronavirus disease (COVID-19) real-time polymerase chain reaction were included in the study as the patient group from September 2021 to October 2021, in Tabriz, Iran. Stool specimens were collected from volunteers, and analysis of SCFAs was carried out by a high-performance liquid chromatography system. Results: The amount of acetic acid in the healthy group was 67.88 ± 23.09 µmol/g, while in the group of patients with COVID-19 was 37.04 ± 13.29 µmol/g. Therefore, the concentration of acetic acid in the patient group was significantly (p < 0.001) lower than in the healthy group. Propionic and butyric acid were present in a higher amount in the control group compared with the case group; however, this value was not statistically significant (p > 0.05). Conclusion: This study showed that the concentration of acetic acid as the metabolite caused by gut microbiota is significantly disturbed in patients with COVID-19. Therefore, therapeutic interventions based on gut microbiota metabolites in future research may be effective against COVID-19.

The metabolic, protective, and immune functions of Akkermansia muciniphila.

Numerous studies have almost proven the beneficial effects of gut microbiota in various aspects of human health, and even the gut microbiota is known as a new and forgotten organ. Akkermansia muciniphila, as a member of the gut microbiota, is considered a bacterium with probiotic properties; consequently, it has a remarkable position in microbiome research. This bacterium accounts for about 1-4 % of the total fecal microbiota population and is also considered a health marker. The accumulated evidence has shown a significant association between A. muciniphila and several disorders and diseases, such as obesity, fatty liver disease, diabetes, and even behavioral disorders. On the other hand, the beneficial effects of A. muciniphila in different studies have shown, such as protective role against pathogenic agents, antitumor properties, tight junctions' improvement, reduction of inflammation, gut permeability, and boosting adaptive immune responses. In this review, based on the available evidence and the latest research, we comprehensively evaluated the impact of A. muciniphila on host health from three points of view: metabolic, protective, and immune functions, as well as the possible mechanisms of each process.

Inhibitory effect of isolated Lactobacillus from oral cavity against bacterial Pathogens and its effect on health promotion / Efecto inhibidor de Lactobacillus aislado de la cavidad oral contra patógenos bacterianos y su efecto en la promoción de la salud

Aims: To determine the inhibitory effect of oral Lactobacillus against bacterial pathogens and investigate correlation between presence of Lactobacillus strains and health promotion. Method: One hundred saliva samples were collected from oral cavity of domestic dairy consumers and were investigated for the isolation and identification of Lactobacillus strain by conventional culture and sequencing of 16SrRNA. Furthermore, well diffusion assay was performed to determination of antibacterial activity of Lactobacillus strains against bacterial pathogens including Salmonella typhimurium, Klebsiella pneumoniae, Shigella sonnei, Shigella dysenteriae, Enterococcus faecalis and Enterococcus faecium. Finally, association between health condition and isolation of Lactobacillus were investigated and obtained data using questionary form were analysed by chi-square test. Results: Thirty Lactobacillus strains recovered from 100 hundred saliva samples. The most common isolated strain was L. gasseri (n=18) and followed by L. vaginalis (n=3) and L. salivarius (n=3). All Lactobacillus strains demonstrated antibacterial activity against at least one of the investigated pathogens. However, the strongest results were obtained by L. vaginalis against K. pneumonia. The correlation between the presence of thirty Lactobacillus strains and health promotion not found. However, only L. gasseri species has significant positive impact on health in their hosts (P < 0.05). Conclusion: Only some Lactobacillus species have a positive impact on health promotion. Despite of weak activity against the investigated pathogens, L. gasseri has a positive impact on the mental problem (intense anger and depression) of their hosts

Objetivos: Determinar el efecto inhibidor del Lactobacillus aislado de la cavidad oral contra patógenos bacterianos e investigar la correlación entre la presencia de cepas de Lactobacillus y la promoción de la salud. Método: se recolectaron cien muestras de saliva de la cavidad oral de consumidores de productos lácteos y se investigó el aislamiento e identificación de la cepa de Lactobacillus mediante cultivo convencional y secuenciación de 16SrRNA. Además, se realizó un ensayo de difusión en pocillos para determinar la actividad antibacteriana de las cepas de Lactobacillus contra patógenos bacterianos que incluyen Salmonella typhimurium, Klebsiella pneumoniae, Shigella sonnei, Shigella dysenteriae, Enterococcus faecalis y Enterococcus faecium. Finalmente, se investigó la asociación entre el estado de salud y el aislamiento de Lactobacillus y se obtuvieron los datos utilizando el cuestionario mediante la prueba de chi-cuadrado. Resultados: Se aislaron treinta cepas de Lactobacillus de 100 muestras de saliva. La cepa aislada más común fue L. gasseri (n = 18), seguida por L. vaginalis (n = 3) y L. salivarius (n = 3). Todas las cepas de Lactobacillus demostraron actividad antibacteriana contra al menos uno de los patógenos investigados Sin embargo, los resultados más fuertes fueron obtenidos por L. vaginalis contra K. pneumonia. No se encontraron correlación entre la presencia de algunas de las treinta cepas de Lactobacillus y la promoción de la salud. Sin embargo, solo la especie L. gasseri tuvo un impacto positivo significativo en la salud de sus hospedadores (P <0,05). Conclusión: solo algunas especies de Lactobacillus tienen un impacto positivo en la promoción de la salud. A pesar de la actividad débil contra los patógenos investigados, L. gasseri tiene un impacto positivo en el problema mental (ira intensa y depresión) de sus huéspedes