Bioscience of Microbiota, Food and Health最新文献

In this letter, an experimental therapy in four patients with therapy-resistant Clostridioides difficile infection is described. These four patients were treated with Manuka honey via colon lavage. First, the patients received a three-day fidaxomicin treatment. The colon lavage was performed on the third day. During a subsequent ileocolonoscopy, 300 mL 15% Manuka honey was applied via a spray catheter. Patients remained in bed for two hours after the procedure and did not defecate. The patient's microbiomes were tested before treatment, after the fidaxomicin treatment, and after honey lavage. A decrease in C. difficile load was found in their microbiomes. Additionally, restoration of microbiota diversity after the honey lavage was also noted. The four patients experienced complete cessation of watery stools and remain symptom free. These results indicate the need for more clinical research into this matter.

Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is widely used as a starter for yogurt and cheese worldwide. Despite the economic importance of this bacterium in the dairy industry, there have been few genetic studies involving knockout or overexpression mutants to identify the functions of L. bulgaricus genes. One of the main reasons for this gap is the low transformation efficiency of available L. bulgaricus chromosome-integrating vectors upon performing conventional electroporation. We previously proposed the conjugal plasmid pAMβ1 as an integration vector for L. bulgaricus, as conjugation could avert the need for a restriction modification system; pAMβ1 does not replicate and integrate into the chromosome of L. bulgaricus. Here, we describe an effective chromosomal manipulation system involving a novel shuttle vector pGMβ1, which could improve the operability of the broad host-range conjugal plasmid pAMβ1. We further developed an enhanced filter-mating method for conjugation. To validate this system, the effectiveness of conversion of the lactate dehydrogenase gene D-ldh of L. bulgaricus to the L-ldh form of Streptococcus thermophilus was examined. As pGMβ1 and pAMβ1 are unable to replicate in L. delbrueckii subsp. delbrueckii, they were chromosomally integrated. However, these plasmids could replicate in L. delbrueckii subsp. indicus and sunkii. This integration system could unearth important gene functions in L. bulgaricus and thus improve its applications in the dairy industry. Moreover, this conjugation system could be used as a stable vector for the transformation of long cluster genes in several species of lactic acid bacteria.

This study aimed to investigate the effect of gestational weight gain on total oxidative stress (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), dietary antioxidant intake, and the gut microbiome. The study was carried out on 40 pregnant women divided as follows: a) normal prepregnancy weight and gestational weight gain of 11.5-16.0 kg (n=10) b) normal prepregnancy weight and gestational weight gain of >16.0 kg (n=10) c) obese before pregnancy and gestational weight gain of 5-9 kg (n=10) and d) obese before pregnancy and gestational weight gain of >9.0 kg (n=10). Serum TOS and TAC levels, dietary antioxidant intake, and microbiome diversity of the gut microbiome were evaluated during the third trimester of pregnancy. A positive correlation was found between body mass index (BMI) in the third trimester and serum TOS levels and OSI. In women with normal prepregnancy weight, an increase in the Firmicutes and Bacteroidetes phyla was observed when gestational weight gain was above the recommended values (p<0.05). In women who were obese before pregnancy, an increase only in the Bacteroidetes phylum was observed when gestational weight gain was above the recommended values (p<0.05). A positive correlation was found between Firmicutes/Bacteroidetes and OSI, and a negative correlation was found between Firmicutes/Bacteroidetes and dietary antioxidant intake (p<0.05). Prepregnancy body weight, high serum TOS level, and dietary antioxidant intake are determinant factors for microbial diversity, with increased serum TOS levels caused by increased gestational weight gain.

Dysbiosis of gut microbiota has adverse effects on host health. This study aimed to determine the effects of changes of faecal microbiota in obese and diabetic rats on the imputed production of enzymes involved in the metabolism of glutamate, gamma-aminobutyric acid (GABA), and succinate. The levels of glutamate decarboxylase, GABA transaminase, succinate-semialdehyde dehydrogenase, and methylisocitrate lyase were reduced or absent in diabetic rats compared with controls and obese rats. Glutamate decarboxylase (GAD) was significantly reduced in obese rats compared with control rats, while the other enzymes were unaltered; different bacterial taxa are suggested to be involved. Levels of bacterial enzymes were inversely correlated with the blood glucose level. These findings suggest that the absence of GABA and reduced succinate metabolism from gut microbiota contribute to the diabetic state in rats.

Creatine is an organic compound which is utilized in biological activities, especially for adenosine triphosphate (ATP) production in the phosphocreatine system. This is a well-known biochemical reaction that is generally recognized as being mainly driven in specific parts of the body, such as the skeletal muscle and brain. However, our report shows a novel aspect of creatine utilization and ATP synthesis in innate immune cells. Creatine supplementation enhanced immune responses in neutrophils, such as cytokine production, reactive oxygen species (ROS) production, phagocytosis, and NETosis, which were characterized as antibacterial activities. This creatine-induced functional upregulation of neutrophils provided a protective effect in a murine bacterial sepsis model. The mortality rate in mice challenged with Escherichia coli K-12 was decreased by creatine supplementation compared with the control treatment. Corresponding to this decrease in mortality, we found that creatine supplementation decreased blood pro-inflammatory cytokine levels and bacterial colonization in organs. Creatine supplementation significantly increased the cellular ATP level in neutrophils compared with the control treatment. This ATP increase was due to the phosphocreatine system in the creatine-treated neutrophils. In addition, extracellular creatine was used in this ATP synthesis, as inhibition of creatine uptake abolished the increase in ATP in the creatine-treated neutrophils. Thus, creatine is an effective nutrient for modifying the immunological function of neutrophils, which contributes to enhancement of antibacterial immunity.

In human medicine, fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridioides difficile infection. It has also been tested as a treatment for multiple gastrointestinal diseases, including inflammatory bowel disease (IBD). However, only a few studies have focused on the changes in the microbiome following FMT for canine IBD. Here, we performed FMT in nine dogs with IBD using the fecal matter of healthy dogs and investigated the subsequent changes in the fecal microbiome and clinical signs. In three dogs, the fecal microbiome was examined by 16S rRNA sequencing. Fusobacteria were observed at a low proportion in dogs with IBD. However, the post-FMT microbiome became diverse and showed a significant increase in Fusobacteria proportion. Fusobacterium was detected in the nine dogs by quantitative polymerase chain reaction. The proportion of Fusobacterium in the post-FMT fecal microbiome was significantly increased (p<0.05). The changes in clinical signs (e.g., vomiting, diarrhea, and weight loss) were evaluated according to the canine inflammatory bowel disease activity index. The score of this index significantly decreased in all dogs (p<0.05) with improvements in clinical signs. These improvements were related to the changes in the proportion of microbes, particularly the increase in Fusobacterium. The dogs with IBD showed a lower proportion of Fusobacterium than healthy dogs. This suggests that a low proportion of Fusobacterium is a characteristic feature of canine IBD and that Fusobacterium is involved in this disease. The results of this study may help elucidate the pathogenesis of this disease and its association with Fusobacterium.

[This corrects the article on p. 49 in vol. 38, PMID: 31106107.].

Heat-killed Lactobacillus plantarum L-137 (HK L-137) has anti-allergic, antitumor, and antiviral effects in mice, as well as an anti-inflammatory effect in rats with metabolic syndrome through regulation of immunity. To evaluate the influence of HK L-137 on chronic inflammation in mice with diet-induced obesity, C57BL/6 J mice were fed a normal diet (16% of energy as fat) or a high-fat diet (62% of energy as fat) with or without 0.002% HK L-137 for 4 to 20 weeks. It was found that HK L-137 supplementation alleviated weight gain and elevation of plasma glucose, cholesterol, alanine aminotransferase, and aspartate transaminase levels in mice with diet-induced obesity. Expression of several inflammation-related genes, including F4/80, CD11c, and IL-1β, in the epididymal adipose tissue of these mice was significantly downregulated by HK L-137. In addition, plasma levels of lipopolysaccharide-binding protein, a marker of endotoxemia, tended to be decreased by administration of HK L-137. These findings suggest that HK L-137 supplementation ameliorates obesity-induced metabolic abnormalities and adipose tissue inflammation, possibly through improvement of intestinal permeability.