Significant Microbial Changes Research Articles

Microbial changes and associated metabolic responses modify host plant adaptation in Stephanitis nashi.

Symbiotic microorganisms are essential for the physiological processes of herbivorous pests, including the pear lace bug Stephanitis nashi, which is known for causing extensive damage to garden plants and fruit trees due to its exceptional adaptability to diverse host plants. However, the specific functional effects of the microbiome on the adaptation of S.nashi to its host plants remains unclear. Here, we identified significant microbial changes in S.nashi on 2 different host plants, crabapple and cherry blossom, characterized by the differences in fungal diversity as well as bacterial and fungal community structures, with abundant correlations between bacteria or fungi. Consistent with the microbiome changes, S.nashi that fed on cherry blossom demonstrated decreased metabolites and downregulated key metabolic pathways, such as the arginine and mitogen-activated protein kinase signaling pathway, which were crucial for host plant adaptation. Furthermore, correlation analysis unveiled numerous correlations between differential microorganisms and differential metabolites, which were influenced by the interactions between bacteria or fungi. These differential bacteria, fungi, and associated metabolites may modify the key metabolic pathways in S.nashi, aiding its adaptation to different host plants. These results provide valuable insights into the alteration in microbiome and function of S.nashi adapted to different host plants, contributing to a better understanding of pest invasion and dispersal from a microbial perspective.

Significant Microbial Changes Are Evident in the Reproductive Tract of Pregnant Rhesus Monkeys at Mid-Gestation but Their Gut Microbiome Does Not Shift until Late Gestation.

Vaginal and rectal specimens were obtained from cycling, pregnant, and nursing rhesus monkeys to assess pregnancy-related changes in the commensal bacteria in their reproductive and intestinal tracts. Using 16S rRNA gene amplicon sequencing, significant differences were found only in the vagina at mid-gestation, not in the hindgut. To verify the apparent stability in gut bacterial composition at mid-gestation, the experiment was repeated with additional monkeys, and similar results were found with both 16S rRNA gene amplicon and metagenomic sequencing. A follow-up study investigated if bacterial changes in the hindgut might occur later in pregnancy. Gravid females were assessed closer to term and compared to nonpregnant females. By late pregnancy, significant differences in bacterial composition, including an increased abundance of 4 species of Lactobacillus and Bifidobacterium adolescentis, were detected, but without a shift in the overall community structure. Progesterone levels were assessed as a possible hormone mediator of bacterial change. The relative abundance of only some taxa (e.g., Bifidobacteriaceae) were specifically associated with progesterone. In summary, pregnancy changes the microbial profiles in monkeys, but the bacterial diversity in their lower reproductive tract is different from women, and the composition of their intestinal symbionts remains stable until late gestation when several Firmicutes become more prominent.

Mixed Nuts as Healthy Snacks: Effect on Tryptophan Metabolism and Cardiovascular Risk Factors.

We recently demonstrated that the consumption of mixed tree nuts (MTNs) during caloric restriction decreased cardiovascular risk factors and increased satiety. Tryptophan (Trp) metabolism has been indicated as a factor in cardiovascular disease. Here, we investigated the effect of MTNs on Trp metabolism and the link to cardiovascular risk markers. Plasma and stool were collected from 95 overweight individuals who consumed either MTNs (or pretzels) daily as part of a hypocaloric weight loss diet for 12 weeks followed by an isocaloric weight maintenance program for an additional 12 weeks. Plasma and fecal samples were evaluated for Trp metabolites by LC-MS and for gut microbiota by 16S rRNA sequencing. Trp-kynurenine metabolism was reduced only in the MTNs group during weight loss (baseline vs. week 12). Changes in Trp-serotonin (week 24) and Trp-indole (week 12) metabolism from baseline were increased in the MTNs group compared to the pretzel group. Intergroup analysis between MTN and pretzel groups does not identify significant microbial changes as indicated by alpha diversity and beta diversity. Changes in the relative abundance of genus Paludicola during intervention are statistically different between the MTNs and pretzel group with p < 0.001 (q = 0.07). Our findings suggest that consumption of MTNs affects Trp host and microbial metabolism in overweight and obese subjects.

Prolonged mask wearing does not alter the oral microbiome, salivary flow rate or gingival health status - A pilot study.

The COVID-19 pandemic has resulted in the widespread use of N95 respirators and surgical masks, with anecdotal reports among healthcare providers and the public of xerostomia, halitosis, and gingivitis, a consortium of symptoms colloquially termed "mask mouth". However, this has not been scientifically verified. The aim of this study was to assess changes in salivary flow rate, gingival health status and oral microbiome associated with prolonged mask use. A total of 25 dental students (mean age = 26.36 ± 1.58) were included in the study and evaluated at three time points: T1, at the end of at least 2 months of full-day mask wear (7.26 ± 1.56 hours/day); T2, at the end of a period of minimal mask use (1.13 ± 1.13 hours/day); and T3, at the end of 2-3 weeks of resuming full-day mask wear (6.93 ± 1.80 hours/day). Unstimulated whole saliva (UWS) flow rate, xerostomia (on a quantitative scale of 10), gingival index (GI) and plaque index (PI) were assessed at each time point. The salivary microbiome was characterized using 16S rRNA gene sequencing. Overall, UWS flow rates were normal (mean of 0.679 ml/min) and xerostomia, PI and GI scores were low (Mean of 3.11, 0.33 and 0.69, respectively) with no significant differences as a result of prolonged mask wearing. Similarly, there were no significant microbial changes at a false discovery rate (FDR) ≤ 0.05. However, some trends were identified using a nominal p-value cut-off of ≤ 0.01, namely Gemella sanguinis, Streptococcus sp. Oral taxon 066 and Oral taxon 058 were associated with prolonged mask wear. Trends were also seen by gender, race and age, for example an increase in P. gingivalis and P. intermedia with age. In conclusion, we found no evidence that prolonged mask wear adversely affects oral health. The findings support that the oral microbiome of healthy individuals is resilient.

Nutrient composition influences the gut microbiota in chronic thoracic spinal cord-injured rats.

Chronic spinal cord injury (SCI) results in an increased predisposition to various metabolic problems that can be exacerbated by consuming a diet rich in calories and saturated fat. In addition, gastrointestinal symptoms have been reported after SCI, including intestinal dysbiosis of the gut microbiome. The effects of both diet and SCI on the gut microbiome of adult male Long Evans rats euthanized 16 wk after injury were investigated. The rats were either thoracic spinal contused or received sham procedures. After 12 wk of either a low-fat or high-fat diet, cecal contents were analyzed, revealing significant microbial changes to every taxonomic level below the kingdom level. Shannon α diversity analyses demonstrated a significant difference in diversity between the groups based on the surgical condition of the rats. SCI produced a unique signature of changes in commensal bacteria that were significantly different than Sham. Specific changes in commensal bacteria as a result of diet manipulation had high fidelity with reports in the literature, such as Clostridia, Thiohalorhabdales, and Pseudomonadales. In addition, novel changes in commensal bacteria were identified that are unique dietary influences on SCI. Linear regression analysis on body fat and lean mass showed that a consequence of chronic SCI produces uncoupled associations between some commensal bacteria and body composition. In conclusion, despite tightly controlling the protein content and varying the carbohydrate and fat contents, Sham and SCI rats respond uniquely to diet. These data provide potential direction for therapeutic modulation of the microbiome to improve health and wellness following SCI.

High throughput sequencing study of foliose lichen-associated bacterial communities from India.

Lichens comprise highly diverse and complex microbial communities, the majority consisting of mycobiont, photobiont, Basidiomycetes yeast and bacteriobiont (internal bacterial communities). In this study, bacterial diversity of foliose lichen was reported. Next generation sequence (NGS) such as Illumina Sequencing (150*2) of 16S rRNA (V3 and V6 region) was used to delineate the bacterial communities associated with five foliose lichen samples. Bacterial sequences obtained from lichen samples suggested that, they harboured bacterial community with variable relative abundances. Among all bacterial communities, Alphaproteobacteria were dominant in all the tested lichen samples. The principal coordinate analysis, Venn and bar chart showed significant microbial changes between the different useful bacterial lineages across the lichens. The relative abundance of dominant and rare bacterial species found were varied, diverse, distinct and unique in each lichen. The Proteobacteria 48.19%, Actinobacteria 25.70%, Bacteroidetes 8.53%, Acidobacteria 9.36% and Chloroflexi 0.83% were predominant in all tested lichens. The present empirical study enhances the confirmed knowledge of bacterial diversity inevitably associated with lichens and is the first report on lichenized bacterial diversity and perhaps their potential possible role in lichen symbiosis in addition to phycobiont and mycobiont.

The Gut Microbiome in Polycystic Ovary Syndrome and Its Association with Metabolic Traits.

Despite the gut microbiome being widely studied in metabolic diseases, its role in polycystic ovary syndrome (PCOS) has been scarcely investigated. Compare the gut microbiome in late fertile age women with and without PCOS and investigate whether changes in the gut microbiome correlate with PCOS-related metabolic parameters. Prospective, case-control study using the Northern Finland Birth Cohort 1966. General community. A total of 102 PCOS women and 201 age- and body mass index (BMI)-matched non-PCOS control women. Clinical and biochemical characteristics of the participants were assessed at ages 31 and 46 and analyzed in the context of gut microbiome data at the age of 46. (s): None. Bacterial diversity, relative abundance, and correlations with PCOS-related metabolic measures. Bacterial diversity indices did not differ significantly between PCOS and controls (Shannon diversity P = .979, unweighted UniFrac P = .175). Four genera whose balance helps to differentiate between PCOS and non-PCOS were identified. In the whole cohort, the abundance of 2 genera from Clostridiales, Ruminococcaceae UCG-002, and Clostridiales Family XIII AD3011 group, were correlated with several PCOS-related markers. Prediabetic PCOS women had significantly lower alpha diversity (Shannon diversity P = .018) and markedly increased abundance of genus Dorea (false discovery rate = 0.03) compared with women with normal glucose tolerance. PCOS and non-PCOS women at late fertile age with similar BMI do not significantly differ in their gut microbial profiles. However, there are significant microbial changes in PCOS individuals depending on their metabolic health.

Influence of Maternal Prepregnancy Obesity and Excessive Gestational Weight Gain on Maternal and Child Gastrointestinal Microbiome Composition: A Systematic Review.

Maternal obesity is a well-known risk factor for significant obstetric and neonatal complications. The influence of the gastrointestinal microbiome in the setting of maternal obesity during pregnancy is less understood. The purpose of this systematic review is to synthesize the literature on the relationships between maternal obesity and excessive gestational weight gain (EGWG) and the composition of maternal and child gastrointestinal microbiomes. We searched CINHAL, OVID Medline, Web of Science, and PubMed for relevant literature using medical subject heading terms related to obesity, pregnancy, and the gastrointestinal microbiome. We assessed 249 articles for potential inclusion using the preferred reporting items for systematic review and meta-analyses framework and deemed 11 articles as relevant for this review. Maternal obesity was associated with significant microbial changes in both maternal and infant fecal microbiome biospecimens including increases in Bacteroidetes, Firmicutes, and the Actinobacteria phyla and decreases in Bifidobacteria. However, inconsistencies in uniform taxonomic results across all studies mean that evidence of specific microbial associations with obesity and EGWG is inconclusive. Our findings suggest that both maternal and child gastrointestinal microbiome composition is altered in the setting of maternal obesity and EGWG during pregnancy. Future microbiome studies should concentrate on the investigation of metagenomic sequencing to elucidate microbial function rather than solely taxonomic composition. More diverse populations of mothers should be sampled to address health disparities and adverse outcomes of underrepresented populations. Finally, analytic pipelines should be standardized across studies to aid in reproducibility.

Metformin alters the duodenal microbiome and decreases the incidence of pancreatic ductal adenocarcinoma promoted by diet-induced obesity.

Pancreatic ductal adenocarcinoma (PDAC)'s growing incidence has been linked to the rise in obesity and type 2 diabetes mellitus. In previous work, we have shown that metformin can prevent the increased incidence of PDAC in a KrasG12D mouse model subjected to a diet high in fat and calories (HFCD). One potential way that metformin can affect the host is through alterations in the gut microbiome. Therefore, we investigated microbial associations with PDAC development and metformin use in the same mouse model. Lox-Stop-Lox Kras G12D/+ (LSL-Kras G12D/+); p48-Cre (KC) mice were given control diet, HFCD, or HFCD with 5 mg/mL metformin in drinking water for 3 mo. At the end of the 3 mo, 16S rRNA sequencing was performed to characterize microbiome composition of duodenal mucosal, duodenal luminal, and cecal luminal samples. KC mice on an HFCD demonstrated depletion of intact acini and formation of advanced pancreatic intraepithelial neoplasia. This effect was completely abrogated by metformin treatment. HFCD was associated with significant changes in microbial composition and diversity in the duodenal mucosa and lumen, much of which was prevented by metformin. In particular, Clostridium sensu stricto was negatively correlated with percent intact acini and seemed to be inhibited by the addition of metformin while on an HFCD. Administration of metformin eliminated PDAC formation in KC mice. This change was associated with significant microbial changes in both the mucosal and luminal microbiome of the duodenum. This suggests that the microbiome may be a potential mediator of the chemopreventive effects of metformin.NEW & NOTEWORTHY Pancreatic ductal adenocarcinoma (PDAC)'s growing incidence has been linked to the rise in obesity and type 2 diabetes mellitus. Administration of metformin eliminated PDAC formation in KC mice with diet-induced obesity. This change was associated with significant microbial changes in both the mucosal and luminal microbiome of the duodenum. This suggests that the microbiome may be a potential mediator of the chemopreventive effects of metformin.

Anti-tumor necrosis factor α therapy associates to type 17 helper T lymphocytes immunological shift and significant microbial changes in dextran sodium sulphate colitis.

BACKGROUNDAnti-tumor necrosis factor α (TNFα) represents the best therapeutic option to induce mucosal healing and clinical remission in patients with moderate-severe ulcerative colitis. On the other side gut microbiota plays a crucial role in pathogenesis of ulcerative colitis but few information exists on how microbiota changes following anti-TNFα therapy and on microbiota role in mucosal healing.AIMTo elucidate whether gut microbiota and immune system changes appear following anti TNFα therapy during dextran sulfate sodium (DSS) colitis.METHODSEighty C57BL/6 mice were divided into four groups: “No DSS”, “No DSS + anti-TNFα”, “DSS” and “DSS + anti-TNFα”. “DSS” and “DSS + anti-TNFα” were treated for 5 d with 3% DSS. At day 3, mice whithin “No DSS+anti-TNFα” and “DSS+anti-TNFα” group received 5 mg/kg of an anti-TNFα agent. Forty mice were sacrificed at day 5, forty at day 12, after one week of recovery post DSS. The severity of colitis was assessed by a clinical score (Disease Activity Index), colon length and histology. Bacteria such as Bacteroides, Clostridiaceae, Enterococcaceae and Fecalibacterium prausnitzii (F. prausnitzii) were evaluated by quantitative PCR. Type 1 helper T lymphocytes (Th1), type 17 helper T lymphocytes (Th17) and CD4+ regulatory T lymphocytes (Treg) distributions in the mesenteric lymph node (MLN) were studied by flow cytometry.RESULTSBacteria associated with a healthy state (i.e., such as Bacteroides, Clostridiaceae and F. prausnitzii) decreased during colitis and increased in course of anti-TNFα treatment. Conversely, microorganisms belonging to Enterococcaceae genera, which are linked to inflammatory processes, showed an opposite trend. Furthermore, in colitic mice treated with anti-TNFα microbial changes were associated with an initial increase (day 5 of the colitis) in Treg cells and a consequent decrease (day 12 post DSS) in Th1 and Th17 frequency cells. Healthy mice treated with anti-TNFα showed the same histological, microbial and immune features of untreated colitic mice. “No DSS + anti-TNFα” group showed a lymphomononuclear infiltrate both at 5th and 12th d at hematoxylin and eosin staining, an increase of in Th1 and Th17 frequency at day 12, an increase of Enterococcaceae at day 5, a decrease of Bacteroides and Clostridiaceae at day 12.CONCLUSIONAnti-TNFα treatment in experimental model of colitis improves disease activity but it is associated to an increase in Th17 pathway together with gut microbiota alteration.

Evaluation of quality index of salted Korean cabbage in the short-term distribution system

The aim of this study was to provide the quality index of salted Korean cabbage in a short-term distribution system. Salted Korean cabbages were packaged with or without 2% salt water, and then distributed in a conventional system (CVS) and a cold-chain system (CCS) for 6 h. The material temperature of samples with and without salt water gradually increased to 19.57°C and 19.43°C in a CVS, respectively and to 10.73°C and 12.90°C in a CCS, respectively. Salinity of the materials in a CCS did not change, whereas salinities of the materials in a CVS were 1.2 and 1.7 fold higher, respectively. Also, a slight increase in acidity was observed in both packaging materials in a CCS. In the case of a CVS, total aerobic bacteria and lactic acid bacteria increased to 7.62 log CFU/g and 6.77 log CFU/g in the materials with salt water, respectively, whereas the number of total aerobic bacteria and lactic acid bacteria ranged between 5.62-5.85 log CFU/g and 4.33-4.83 log CFU/g in the materials without salt water, respectively. However, significant microbial changes were not observed in a CCS as distribution time increased. CCS with salt water packaging was effective in achieving microbial control and maintaining physicochemical quality. Salinity, aerobic bacteria, and lactic acid bacteria can be useful as quality indices for a CVS, and acidity can be useful as quality index for a CCS.

Chlorpyrifos Exposure During Perinatal Period Affects Intestinal Microbiota Associated With Delay of Maturation of Digestive Tract in Rats.

Pesticide exposure via residues in food may be especially harmful when it takes place in the developing child. The present study was designed to assess the impact of perinatal exposure to chlorpyrifos (CPF, an insecticide known to cross the placental barrier). Female rats were exposed to oral CPF (1 or 5 mg kg day vs vehicle controls) from gestation onset up to weaning of the pups that were individually gavaged (CPF or vehicle) thereafter. Two developmental time points were studied: weaning (day 21) and adulthood (day 60). After sacrifice, samples from the intestinal tract and other organs underwent microbiological and histological analyses. Rat pups exposed to 5 mg kg day CPF were both significantly smaller (body length) and lighter than controls. Exposure to CPF was associated with changes in the histological structures (shorter and thinner intestinal villosities), an intestinal microbial dysbiosis, and increased bacterial translocation in the spleen and liver. These significant microbial changes in the gut were associated with impaired epithelium protection (mucin-2) and microbial pattern recognition receptor (Toll-like 2 and 4) gene expression. Exposure to CPF during gestation and development affected the pups' intestinal development, with morphological alteration of the structures involved in nutrient absorption, intestinal microbial dysbiosis, alteration of mucosal barrier (mucin-2), stimulation of the innate immune system, and increased bacterial translocation. Perinatal exposure to CPF may therefore have short- and long-term impacts on the digestive tract.