Short chain fatty acids (SCFAs) being produced during fermentation of non-digestible polysaccharides are regulatory compounds with the potential to influence inflammatory, as well as emotional state and cognition through the gut–brain axis. We analyzed the association between stool concentration of SCFAs (acetic acid (C 2:0), propionic acid (C 3:0), isobutyric acid (C 4:0 i), butyric acid (C 4:0 n), isovaleric acid (C 5:0 i) valeric acid (C 5:0 n), isocaproic acid (C 6:0 i), caproic acid, and (C 6:0 n) heptanoic acid (C 7:0)) and depressive symptoms among women and looked for the potential confounders of microbiota byproduct synthesis. We enrolled 116 women aged 52.0 ± 4.7 years and recognized depression in 47 (40.52%). To analyze the emotional state, Beck’s Depression Inventory (BDI) was used. We assessed SCFAs content by means of gas chromatography. Fiber intake was estimated using parts of food frequency questionnaire. The content of acetic acid was significantly lowered compared to non-depressed women (median {IQR}: 29.49 {20.81} vs. 34.99 {19.55}, p = 0.04). A tendency toward decreased level of propionic acid was noticed (median {IQR}: 16.88 {9.73} vs. 21.64 {12.17}, p = 0.07), while the concentration of isocaproic acid was significantly increased in (median {IQR}: 0.89 {1.15} vs. 0.56 {0.95}, p < 0.01) comparison to matched healthy subjects. We found negative correlations between acetate, propionate, and Beck’s score (r = −0.2, p = 0.03; r = −0.21, p = 0.02, respectively). Statistically significant correlations between acetate and propionate and BDI somatic score (r = −0.21, p = 0.01; r = −0.17, p = 0.03), as well as correlations regarding isocaproic and both cognitive/affective (r = 0.37, p = 0.0001) and somatic (r = 9.37, p < 0.001) scores were found. Women who declared current usage of lipid-lowering and thyroid drugs in the past, had higher content of C6:0-i (Users; median {IQR}: 1.91 {3.62} vs. non-users; 0.55 {0.67}; p = 0.0048).and lower of C2:0 (Users; median {IQR}: 23.07 {12.80} vs. non users 33.73 {21.44}; p = 0.041), respectively. No correlations regarding SCFAs concentration and fiber intake were found. We concluded that SCFAs may potentially contribute to depression phenotype, however, due to the small size of groups suffering from moderately heavy (n = 5) and severe (n = 7) depression, the conclusion should be treated with caution. Pharmacotherapy of hyperlipidemia and thyroid disease might affect SCFAs synthesis. Studies with more participants are required.

The novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection has been predominantly linked to respiratory distress syndrome, but gastrointestinal symptoms and hepatic injury have also been reported. The mechanism of liver injury is poorly understood and may result as a consequence of viral hepatitis, systemic inflammatory response, gut barrier and microbiome alterations, intensive care treatment or drug toxicity. The incidence of hepatopathy among patients with coronavirus disease 2019 (COVID-19) is unclear, but studies have reported liver injury in patients with SARS and Middle East respiratory syndrome (MERS). We aimed to systematically review data on the prevalence of hepatic impairments and their clinical course in SARS and MERS Coronaviridae infections. A systematic literature search (PubMed/Embase/Cinahl/Web of Science) according to preferred reporting items for systematic review and meta-analysis protocols (PRISMA) was conducted from database inception until 17/03/2020 for studies that evaluated the incidence of hepatic abnormalities in SARS CoV-1, SARS CoV-2 and MERS infected patients with reported liver-related parameters. A total of forty-three studies were included. Liver anomalies were predominantly mild to moderately elevated transaminases, hypoalbuminemia and prolongation of prothrombin time. Histopathology varied between non-specific inflammation, mild steatosis, congestion and massive necrosis. More studies to elucidate the mechanism and importance of liver injury on the clinical course and prognosis in patients with novel SARS-CoV-2 infection are warranted.

Current treatment of major depressive disorder (MDD) often does not achieve full remission of symptoms. Therefore, new forms of treatment and/or adjunct therapy are needed. Evidence has confirmed the modulation of the gut–brain–microbiota axis as a promising approach in MDD patients. The overall purpose of the SANGUT study—a 12-week, randomized, double-blind, and placebo-controlled Study Evaluating the Effect of Probiotic Supplementation on the Mental Status, Inflammation, and Intestinal Barrier in Major Depressive Disorder Patients Using Gluten-free or Gluten-containing Diet — is to determine the effect of interventions focused on the gut-brain-microbiota axis in a group of MDD patients. A total of 120 outpatients will be equally allocated into one of four groups: (1) probiotic supplementation+gluten-free diet group (PRO-GFD), (2) placebo supplementation+ gluten-free diet group (PLA-GFD), (3) probiotic supplementation+ gluten containing diet group (PRO-GD), and (4) placebo supplementation+gluten containing diet group (PLA-GD). PRO groups will receive a mixture of psychobiotics (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175), and GFD groups will follow a gluten-free diet. The intervention will last 12 weeks. The primary outcome measure is change in wellbeing, whereas the secondary outcome measures include physiological parameters. Microbiota and its metabolites have the potential to influence CNS function. Probiotics may restore the eubiosis within the gut while a gluten-free diet, via changes in the microbiota profile and modulation of intestinal permeability, may alter the activity of microbiota-gut-brain axis previously found to be associated with the pathophysiology of depression. It is also noteworthy that microbiota being able to digest gluten may play a role in formation of peptides with different immunogenic capacities. Thus, the combination of a gluten-free diet and probiotic supplementation may inhibit the immune-inflammatory cascade in MDD course and improve both psychiatric and gut barrier-associated traits. NCT03877393 .