IL-10 Expression-Inducing Gut Bacteria Alleviate High-Fat Diet-Induced Obesity and Hyperlipidemia in Mice

Lactobacillus acidophilus KLDS1.0901 ameliorates non-alcoholic fatty liver disease by modulating the tryptophan metabolite indole-3-aldehyde and acting on its receptor AhR

Our previous study demonstrated that Lactobacillus acidophilus KLDS1.0901 significantly alleviated symptoms of high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) and showed a strong association with the gut microbiota; however, the underlying mechanisms remained unclear. In this study, we focused on changes in intestinal metabolic pathways in mice following intervention with Lactobacillus acidophilus KLDS1.0901, using non-targeted metabolomics. Tryptophan metabolism was found to be closely associated with NAFLD alleviation, and indole-3-aldehyde (IAld) was identified as a key target. Animal experiments showed no significant differences in the levels of liver triglycerides, fasting blood glucose, alanine aminotransferase, aspartate aminotransferase, IL-6, IL-1β, TNF-α, and IL-10 between the direct-feeding IAld group and the Lactobacillus acidophilus KLDS1.0901 group. This suggests that the IAId, produced by Lactobacillus acidophilus KLDS1.0901, is the key intermediate mediator responsible for its improvement of NAFLD. The alleviating effect of Lactobacillus acidophilus KLDS1.0901 on NAFLD symptoms was suppressed after the inhibition of the IAld receptor aromatic hydrocarbon receptor (AhR), suggesting that the bacterium relies on the AhR signaling pathway to mediate its effect on NAFLD. Cellular experiments showed that IAld significantly reduced triglyceride content, decreased lipid accumulation, and increased glycogen levels in oleic acid-induced cells. The effects of IAld on gene transcription levels in oleic acid-induced HepG2 cells were further analyzed using high-throughput sequencing. Transcriptomic analysis revealed that IAld regulates key pathways, including the NF-κB, chemokine and AGE-RAGE signaling pathways. Our study identified the ameliorative effects of tryptophan metabolites, particularly IAld, on NAFLD, along with the underlying mechanisms, offering new insights into potential treatment strategies for NAFLD.

Nutraceutical composition (yeast β-glucan, prebiotics, minerals, and silymarin) predicts improvement of sleep quality and metabolic parameters: A randomized pilot study

BACKGROUND & AIMS

The search for integrative and natural therapies that favor homeostasis to boost sleep and diet quality took place for young adult populations as a non-pharmacological strategy for long-term good quality of life. Thus, the present pilot study aims to investigate the effects of 90-day consumption of a nutraceutical composition on the neuro-immune-endocrine axis, providing better sleep quality and health improvement.

METHODS

For this, from March 2021 to June 2021, twenty-two Brazilian young adult volunteers (women and men) with BMI between 18.5 and 34.9 kg/m2 were divided into three distinct supplementation groups: NSupple; NSupple plus_S, and NSupple plus. Briefly, the supplement compositions included yeast β-glucan, prebiotics, and minerals in different concentrations associated or not with the herbal medicine silymarin. Neither nutritional nor physical activity interventions were performed during this pilot study period. The anthropometrics measures, questionnaires answer data, and harvest blood for metabolic, inflammatory, and hormonal tests were collected at baseline time (day zero-T0) and day 90 (T90) post-supplementation.

RESULTS

Our results highlight that the supplementation reduced body mass index (BMI), Waist-to-height ratio (WHtR), waist circumference, AST/ALT ratio, alkaline phosphatase, and HbA1c. Post-supplementation the IL-6 and IL-10 levels and the sleep, humor, and quality of life scores were suggested to improve. Sleep quality improvement seems to predict the reduction of adiposity-related body measures.

CONCLUSION

In sum, the nutraceutical supplementation might be related to anthropometric, metabolic, and endocrine parameters after 90 days reflecting on perception of humor, sleep, and life quality enhancement. However, it is important to recognize the limitation of the data presented considering that this was a pilot study.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT04810572 registered on 20th February 2021.

Are probiotics effective in reducing the metabolic side effects of psychiatric medication? A scoping review of evidence from clinical studies

The psychopharmacological treatment of patients with schizophrenia or depression is often accompanied by serious side effects. In particular, the clinical findings of weight gain are worrying, as this side effect can lead to various medical sequelae in the future. However, the treatment of metabolic changes in psychiatric patients is often neglected or unsuccessful. An improved knowledge of possible therapeutic approaches is needed. The aim of this study was to provide an overview of the utilisation and effectiveness of probiotics in reducing weight gain in patients with severe mental illness. A scoping review of studies published until 15 June 2022 was conducted to identify studies using probiotics in people with schizophrenia or depression. We systematically searched the databases EMBASE, PubMed (MEDLINE), Web of Science and SCOPUS with a predefined search string. In addition, reference lists of relevant publications were examined for additional studies. The studies were assessed by two reviewers. The primary outcomes were weight-related measurements. The secondary outcomes were metabolic blood parameters and gut microbiota. Four studies ultimately met the inclusion criteria. Two studies in which probiotics were administered did not find significant effects on pharmacologically induced weight gain. The other two studies examined the effects of synbiotics (a combination of probiotics and prebiotics). Interestingly, less weight gain was observed in individuals with this combined intervention. Adjustments in diet can be helpful and are generally well-accepted interventions in the fight against pharmacologically induced weight gain. The clinical use of probiotics and prebiotics (or synbiotics) as dietary interventions may represent a promising additional strategy in this regard. However, the few studies available showed no clear conclusions.

The differential modulatory effects of Eurotium cristatum on the gut microbiota of obese dogs and mice are associated with improvements in metabolic disturbances

Obesity is a disease in humans and companion animals that can cause many chronic diseases. Eurotium cristatum (E. cristatum) is a dominant fungus in Fuzhuan tea. In this study, we aimed to investigate the possibility that E. cristatum may reduce diet-induced obesity by regulating the gut microbiota and measuring the differences in the gut microbiota of obese mice and dogs under E. cristatum supplementation. High-fat diet-fed C57BL/6J mice and beagle dogs were supplemented with live E. cristatum for 8 or 12 weeks. Faecal microbiota transplantation (FMT) and 16S rRNA sequencing were used to evaluate the relationship between the anti-obesity effect of E. cristatum and the gut microbiota. The results suggested that live E. cristatum reduced obesity and metabolic disorders in obese mice and dogs. 16S rRNA sequencing results revealed that E. cristatum decreased the Firmicutes/Bacteroidetes (F/B) ratio and the abundance of members of the Firmicutes phylum, including Lactobacillus gasseri, Lactobacillus reuteri, and Lactobacillus intestinalis, in obese mice, but the opposite was true in obese dogs. Furthermore, to investigate whether the antiobesity effect of E. cristatum can be attributed to gut microbiota, FMT and 16S rRNA sequencing were employed. The FMT trial confirmed that the anti-obesity effect of E. cristatum was mediated by modulating gut dysbiosis. In addition, we isolated live E. cristatum from faeces and found the β-hydroxy acid metabolite of monacolin K (MKA) in E. cristatum culture. Our research implies that E. cristatum has the potential to treat obesity as a novel probiotic.

Lactobacillus rhamnosus and Bifidobacterium longum alleviate colitis and cognitive impairment in mice by regulating IFN-γ to IL-10 and TNF-α to IL-10 expression ratios

Gut lactobacilli and bifidobacteria on the immune homeostasis. Therefore, to understand the mechanism in vivo, we selected human fecal Lactobacillus rhamnosus NK210 and Bifidobacterium longum NK219, which strongly suppressed the IFN-γ to IL-10 expression (IIE) ratio in lipopolysaccharide-stimulated macrophages. Thereafter, we examined their effects on the endotoxin, antibiotics, or antitumor drug-stimulated immune imbalance in mice. Intraperitoneal injection of lipopolysaccharide and oral gavage of ampicillin increased IFN-γ and TNF-α expression in the spleen, colon, and hippocampus, while IL-10 expression decreased. However, intraperitoneal injection of cyclophosphamide suppressed IFN-γ, TNF-α, and IL-10 expression. LPS exposure induced splenic natural killer cell cytotoxicity against YAC-1 cells (sNK-C) and peritoneal macrophage phagocytosis against Candida albicans (pMA-P) activities, while cyclophosphamide and ampicillin treatments suppressed sNK-C and pMA-P activities. However, LPS, ampicillin, cyclophosphamide all increased IIE and TNF-α to IL-10 expression (TIE) ratios. Oral administration of NK210 and/or NK219 significantly reduced LPS-induced sNK-C, pMA-P, and IFN-γ expression, while cyclophosphamide- or ampicillin-suppressed sNK-C and pMA-P activities, cyclophosphamide-suppressed IFN-γ, TNF-α, and IL-10 expression, and ampicillin-suppressed IL-10 expression increased. Nevertheless, they suppressed LPS-, ampicillin-, or cyclophosphamide-induced IIE and TIE ratios, cognitive impairment, and gut dysbiosis. In particular, NK219, but not NK210, increased the IIE expression ratio in vitro and in vivo, and enhanced sNK-C and pMA-P activities in normal control mice, while cognitive function and gut microbiota composition were not significantly affected. These findings suggest that NK210, Lactobacillus sp, and NK219, Bifidobacterium additively or synergistically alleviate gut dysbiosis, inflammation, and cognitive impairment with immune imbalance by controlling IIE and TIE ratios.

Lactobacillus rhamnosus HDB1258 modulates gut microbiota-mediated immune response in mice with or without lipopolysaccharide-induced systemic inflammation

Background

Gut microbiota closely communicate in the immune system to maintain a balanced immune homeostasis in the gastrointestinal tract of the host. Oral administration of probiotics modulates gut microbiota composition. In the present study, we isolated Lactobacillus rhamnosus HDB1258, which induced tumor necrosis factor (TNF)-α and interleukin (IL)-10 expression in macrophages, from the feces of breastfeeding infants and examined how HDB1258 could regulate the homeostatic immune response in mice with or without lipopolysaccharide (LPS)-induced systemic inflammation.

Results

Oral administration of HDB1258 significantly increased splenic NK cell cytotoxicity, peritoneal macrophage phagocytosis, splenic and colonic TNF-α expression, TNF-α to IL-10 expression ratio, and fecal IgA level in control mice, while Th1 and Treg cell differentiation was not affected in the spleen. However, HDB1258 treatment significantly suppressed peritoneal macrophage phagocytosis and blood prostaglandin E2 level in mice with LPS-induced systemic inflammation. Its treatment increased LPS-suppressed ratios of Treg to Th1 cell population, Foxp3 to T-bet expression, and IL-10 to TNF-α expression. Oral administration of HDB1258 significantly decreased LPS-induced colon shortening, myeloperoxidase activity and NF-κB⁺/CD11c⁺ cell population in the colon, while the ratio of IL-10 to TNF-α expression increased. Moreover, HDB1258 treatment shifted gut microbiota composition in mice with and without LPS-induced systemic inflammation: it increased the Cyanobacteria and PAC000664_g (belonging to Bacteroidetes) populations and reduced Deferribacteres and EU622763_s group (belonging to Bacteroidetes) populations. In particular, PAC001066_g and PAC001072_s populations were negatively correlated with the ratio of IL-10 to TNF-α expression in the colon, while the PAC001070_s group population was positively correlated.

Conclusions

Oral administered HDB1258 may enhance the immune response by activating innate immunity including to macrophage phagocytosis and NK cell cytotoxicity in the healthy host and suppress systemic inflammation in the host with inflammation by the modulation of gut microbiota and IL-10 to TNF-α expression ratio in immune cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02192-4.

Regulation of Intestinal Inflammation by Dietary Fats

With the epidemic of human obesity, dietary fats have increasingly become a focal point of biomedical research. Epidemiological studies indicate that high-fat diets (HFDs), especially those rich in long-chain saturated fatty acids (e.g., Western Diet, National Health Examination survey; NHANES 'What We Eat in America' report) have multi-organ pro-inflammatory effects. Experimental studies have confirmed some of these disease associations, and have begun to elaborate mechanisms of disease induction. However, many of the observed effects from epidemiological studies appear to be an over-simplification of the mechanistic complexity that depends on dynamic interactions between the host, the particular fatty acid, and the rather personalized genetics and variability of the gut microbiota. Of interest, experimental studies have shown that certain saturated fats (e.g., lauric and myristic fatty acid-rich coconut oil) could exert the opposite effect; that is, desirable anti-inflammatory and protective mechanisms promoting gut health by unanticipated pathways. Owing to the experimental advantages of laboratory animals for the study of mechanisms under well-controlled dietary settings, we focus this review on the current understanding of how dietary fatty acids impact intestinal biology. We center this discussion on studies from mice and rats, with validation in cell culture systems or human studies. We provide a scoping overview of the most studied diseases mechanisms associated with the induction or prevention of Inflammatory Bowel Disease in rodent models relevant to Crohn's Disease and Ulcerative Colitis after feeding either high-fat diet (HFD) or feed containing specific fatty acid or other target dietary molecule. Finally, we provide a general outlook on areas that have been largely or scarcely studied, and assess the effects of HFDs on acute and chronic forms of intestinal inflammation.