Probiotics modulate gut microbiota and health status in Japanese cedar pollinosis patients during the pollen season

Impact of Fermented Milk On Gut Microbiota And Human Health: A Comprehensive Review

The beneficial impact of gut microbiota on human health has encouraged studies on factors modulating it. Among the different factors, diet plays a vital role in this area. Many studies on animals and humans have been concerned with the effects of fermented milk products on gut microbiota and how they relate to health benefits. Yoghurt, kefir, Koumiss, and fermented kinds of milk made using different probiotic strains were tested for their capability to modulate gut microbiota. It is apparent that the microflora present in fermented milk, specifically probiotics, are capable of enduring the gastrointestinal tract's adverse conditions primarily through transit microorganisms. Meanwhile, they can alter the gut microbiota in several ways that benefit human health. The present article gives a comprehensive overview of the modulation of gut microbiota by consumption of fermented milk, particularly those containing probiotics, and their impact on human health.

Fermented foods affect the seasonal stability of gut bacteria in an Indian rural population

The effect of fermented foods on healthy human gut microbiota structure and function, particularly its seasonal preference and frequent long-term consumption, has been largely uncharacterised. Here, we assess the gut microbiota and metabolite composition of 78 healthy Indian agrarian individuals who differ in the intake of fermented milk and soybean products by seasonal sampling during hot-humid summer, autumn and dry winter. Here we show that, seasonal shifts between the Prevotella- and Bifidobacterium/Ruminococcus-driven community types, or ecological states, and associated fatty acid derivatives, with a bimodal change in Bacteroidota community structure during summer, particularly in fermented milk consumers. Our results associate long-term fermented food consumption with reduced gut microbiota diversity and bacterial load. We identify taxonomic groups that drive the seasonal fluctuation and associated shifts between the two ecological states in gut microbiota. This understanding may pave the way towards developing strategies to sustain a healthy and resilient gut microbiota through dietary interventions.

Probiotics combined with prebiotics alleviated seasonal allergic rhinitis by altering the composition and metabolic function of intestinal microbiota: a prospective, randomized, double-blind, placebo-controlled clinical trial

Background

Numerous studies have established that probiotics or prebiotics can relieve the symptoms of allergic rhinitis (AR), but their mechanism of action remain underexplored. This study aimed to observe the clinical efficacy of probiotics combined with prebiotics in seasonal AR patients and explore their underlying mechanisms.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled clinical trial. The test group was given probiotics combined with prebiotics, whereas the placebo group was administered simulated preparation for 90 days. Outcome measures included total nasal symptom score (TNSS), visual analog scale, rhinitis quality of life questionnaire, fractional exhaled nitric oxide, and the rate and intensity of Loratadine use. Serum TNF-α, INF-γ, IL-4, IL-17, and IgE levels were measured by enzyme-linked immunosorbent assay. Intestinal microbiota was detected by 16S rRNA gene sequencing and quantitative PCR. Short-chain fatty acids were analyzed by gas chromatography-mass spectrometry.

Results

106 participants (N = 53 for both test group and placebo group) completed the study. From baseline to day 91, mean difference between groups (MDBG) in the reduction of TNSS was -1.1 (-2.2, -0.1) (P = 0.04); MDBG in the increment of TNF-α was 7.1 pg/ml (95% CI: 0.8, 13.4, P = 0.03); the INF-γ level was significantly increased (P = 0.01), whereas that of IL-17 (P = 0.005) was significantly decreased in the test group, whilst mean difference within groups was not statistically significant in the placebo group; MDBG in the increment of acetate was 12.4% (95% CI: 7.1%, 17.6%, P <0.001). After the administration of probiotics and prebiotics, the composition and metabolic function of the intestinal microbiota were significantly altered and positively related to the beneficial effect on seasonal AR patients.

Conclusion

Probiotics combined with prebiotics administered for 90 days significantly attenuated the symptoms of seasonal AR patients, which may related to fluctuations in the composition and metabolic function of the intestinal microbiota and further ameliorating host immunity.

Novel probiotic preparation with in vivo gluten-degrading activity and potential modulatory effects on the gut microbiota

Gluten possesses unique properties that render it only partially digestible. Consequently, it exerts detrimental effects on a part of the worldwide population who are afflicted with celiac disease (1%) or related disorders (5%), particularly due to the potential for cross-contamination even when adhering to a gluten-free diet (GFD). Finding solutions to break down gluten during digestion has a high nutritional and social impact. Here, a randomized double-blind placebo-controlled in vivo challenge investigated the gluten-degrading activity of a novel probiotic preparation comprising lactobacilli and their cytoplasmic extracts, Bacillus sp., and bacterial protease. In our clinical trial, we collected feces from 70 healthy volunteers at specific time intervals. Probiotic/placebo administration lasted 32 days, followed by 10 days of wash-out. After preliminary GFD to eliminate residual gluten from feces, increasing amounts of gluten (50 mg-10 g) were administered, each one for 4 consecutive days. Compared to placebo, the feces of volunteers fed with probiotics showed much lower amounts of residual gluten, mainly with increased intakes. Probiotics also regulate the intestinal microbial communities, improving the abundance of genera pivotal to maintaining homeostasis. Quantitative PCR confirmed that all probiotics persisted during the intervention, some also during wash-out. Probiotics promoted a fecal metabolome with potential immunomodulating activity, mainly related to derivatives of branched-chain amino acids and short-chain fatty acids.

IMPORTANCE

The untapped potential of gluten-degrading bacteria and their application in addressing the recognized limitations of gluten-related disorder management and the ongoing risk of cross-contamination even when people follow a gluten-free diet (GFD) emphasizes the significance of the work. Because gluten, a common protein found in many cereals, must be strictly avoided to stop autoimmune reactions and related health problems, celiac disease and gluten sensitivity present difficult hurdles. However, because of the hidden presence of gluten in many food products and the constant danger of cross-contamination during food preparation and processing, total avoidance is frequently challenging. Our study presents a novel probiotic preparation suitable for people suffering from gluten-related disorders during GFD and for healthy individuals because it enhances gluten digestion and promotes gut microbiota functionality.

Fermented foods, their microbiome and its potential in boosting human health

Fermented foods (FFs) are part of the cultural heritage of several populations, and their production dates back 8000 years. Over the last ~150 years, the microbial consortia of many of the most widespread FFs have been characterised, leading in some instances to the standardisation of their production. Nevertheless, limited knowledge exists about the microbial communities of local and traditional FFs and their possible effects on human health. Recent findings suggest they might be a valuable source of novel probiotic strains, enriched in nutrients and highly sustainable for the environment. Despite the increasing number of observational studies and randomised controlled trials, it still remains unclear whether and how regular FF consumption is linked with health outcomes and enrichment of the gut microbiome in health-associated species. This review aims to sum up the knowledge about traditional FFs and their associated microbiomes, outlining the role of fermentation with respect to boosting nutritional profiles and attempting to establish a link between FF consumption and health-beneficial outcomes.

Effects of prebiotics, probiotics and synbiotics on serum creatinine in non-dialysis patients: a meta-analysis of randomized controlled trials

OBJECTIVE

Serum creatinine level are influenced by many factors. Although accumulated data suggested that prebiotics, probiotics and synbiotics supplements could affect serum creatinine level, the results remained controversial. The aim of the present paper was to evaluate the effects of prebiotics, probiotics and synbiotics on serum creatinine in non-dialysis patients.

METHODS

PubMed, EMBASE (Excerpta Medica Database) and the Cochrane Library databases were searched for eligible randomized, controlled trials (RCTs) which were limited to English language studies until 30 September 2022. A random-effects model was performed to analyze the impact of pooled trials.

RESULT

Twelve randomized, controlled trial studies were included in the meta-analysis. Prebiotics, probiotics or synbiotics supplementation did not significantly decrease the serum creatinine levels in non-dialysis patients compared to placebo [standardized mean difference (SMD) = 0.05; 95% confidence interval (CI): (-0.21, 0.31); p = 0.72; I² = 61%].

CONCLUSION

The present meta-analysis indicated that supplementation with prebiotics, probiotics and synbiotics could not act as promising adjuvant therapies to decrease the serum creatinine levels in non-dialysis patients.

Efficacy and safety of gastrointestinal microbiome supplementation for allergic rhinitis: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Allergic rhinitis (AR) is a non-infective chronic inflammatory disease of nasal mucosa.

PURPOSE

To evaluate the efficacy and safety of gastrointestinal microbiome supplementation (GMS) for patients with allergic rhinitis (AR), concerning improvement on symptoms and signs, laboratory outcomes, quality of life, and medication scores.

METHODS

Five English databases were searched up to Dec 12th, 2022. Probiotics, prebiotics, and synbiotics were main therapies or adjuvants in experimental groups. Systematic reviews and meta-analyses were conducted based on the Cochrane systematic review method by using RevMan 5.4 Software, with meta-influence analyses, subgroup-analyses, meta-regression, and publication bias performed for exploration of heterogeneity by Stata V.14. Trial sequential analyses were performed by TSA 0.9, and quality of the results was accessed through the GRADE-pro GDT.

RESULTS

Finally, extracted from 53 articles, 65 RCTs involving 3,634 participants with sound worldwide representativeness were included. Primary results showed better improvement in GMS groups on TNSS (WMD=1.05, P for WMD=0.004, 95%CI:0.34 to 1.76), overall nasal condition (WMD=1.25, P for WMD<0.001, 95%CI:0.90 to 1.61), overall quality of life (WMD=6.16, P for WMD<0.001, 95%CI:4.92 to 7.40) and medication score (WMD=0.42, P for WMD=0.42, 95%CI:-0.06 to 0.90).However, GMS groups were inferior than the controls concerning reduction on serum total IgE (WMD=-1.81) and ratios of serum Th1/Th2 (WMD=-1.06). Meta-regressions suggested significant (p<0.05) variations of the effects in some comparisons. In addition, results of sub-group analyses firstly revealed potential influence between final results and the variables above. Instantly after intervention, the GRADE levels of evidence were sound, including "High ⨁⨁⨁⨁" in 10, "Moderate ⨁⨁⨁◯" in 33, and "Low ⨁⨁◯◯" in nine comparisons. However, overall certainties decreased obviously during follow-ups.

CONCLUSION

Overall, our pooled results firstly revealed that GMS yielded acceptable benefits for patients with AR compared with controls with sound certainties, after balancing the benefits and harms.

Sex Differences in Intestinal Microbiota and Their Association with Some Diseases in a Japanese Population Observed by Analysis Using a Large Dataset

In recent years, many studies have focused on the relationship between intestinal microbiota and human health, but the impact of sex has not yet been sufficiently investigated. In this study, sex differences in the intestinal microbiota of a Japanese population were investigated by age group, using a large dataset constructed for a cross-sectional study. α-diversity analysis indicated that the impact of sex differences varied among the 20s-50s age groups but tended to be smaller among the 60s-70s age groups. Fusobacterium, Megamonas, Megasphaera, Prevotella, and Sutterella were more common among males, whereas Alistipes, Bacteroides, Bifidobacterium, Odoribacter, and Ruthenibacterium were common among females. Next, intestinal bacteria potentially associated with 12 diseases were investigated for each sex. The results indicate that many of these differ between males and females, and among age groups. Thus, sex and age should be considered for studies on intestinal microbiota and disease association, prevention, and treatment approaches that target them.

Effect of adding probiotics to an antibiotic intervention on the human gut microbial diversity and composition: a systematic review

Introduction. Millions of antibiotic prescriptions are written annually in the USA.

Gap Statement. Probiotics reduce antibiotic-induced gastrointestinal side effects; however, the effect of probiotics on preserving gut microbial composition in response to antibiotics is not well understood.

Aim. To evaluate whether the addition of probiotics is capable of reverting the changes in alpha diversity and gut microbial composition commonly observed in adult participants receiving antibiotics.

Methodology. A search was conducted by two researchers following the PRISMA guidelines using PubMed, Science Direct, Cochrane and Embase from January to December 2021 with the following inclusion criteria: (i) randomized clinical trials assessing the effect of antibiotics, probiotics or antibiotics+probiotics; (ii) 16S rRNA; (iii) adult participants; and (iv) in English. Once data was extracted in tables, a third researcher compared, evaluated and merged the collected data. The National Institutes of Health (NIH) rating system was utilized to analyse risk of bias.

Results. A total of 29 articles (n=11 antibiotics, n=11 probiotics and n=7 antibiotics+probiotics) met the inclusion criteria. The lack of standardization of protocols to analyse the gut microbial composition and the wide range of selected antibiotics/probiotics complicated data interpretation; however, despite these discrepancies, probiotic co-administration with antibiotics seemed to prevent some, but not all, of the gut microbial diversity and composition changes induced by antibiotics, including restoration of health-related bacteria such as Faecalibacterium prausnitzii .

Conclusion. Addition of probiotics to antibiotic interventions seems to preserve alpha diversity and ameliorate the changes to gut microbial composition caused by antibiotic interventions.

The Baseline Gut Microbiota Enterotype Directs Lifestyle-Induced Amelioration of Pollen Allergy Severity: A Self Controlled Case-Series Study

Deciphering the key factors underlying individual responses to a habitual diet is important in implementing personalized nutrition strategies to treat allergic diseases. This prospective randomized cohort study aimed to identify key factors determining individual pollen allergy (PA) trajectories in a natural setting. Baseline data on fecal microbiota composition, lifestyle activities, and diet habits of 190 participants with PA and 92 healthy controls were collected, followed by a SOMPO-guided intestinal activity program. Three enterotypes enriched in Bacteroides, Prevotella, and Ruminococcus and four subenterotypes for enterotypes Bacteroides and Prevotella enriched with Faecalibacterium, Megamonas, and Fusobacterium were identified at baseline. PA severity was significantly negatively correlated with the daily intake of fermented plants and no weekly intake of meat, but positively correlated with poor sleep quality. Interactions between enterotype and lifestyle factors affected PA severity, and intestinal activity intervention based on the baseline enterotype reduced the PA severity score. In conclusion, the findings of this study demonstrated that the baseline gut enterotype plays a crucial role in PA. This study suggests combining enterotype data with habitual diet can improve PA severity.

Gut microbiota: A target for prebiotics and probiotics in the intervention and therapy of food allergy

Food allergy has become a major public health problem all over the world. Evidence showed that allergic reactions induced by food proteins often lead to disturbances in the gut microbiota (symbiotic bacteria). Gut microbiota plays an important role in maintaining the balance between intestinal immune tolerance and allergic reactions. Dietary intervention has gradually become an important method for the prevention and treatment of allergic diseases, and changing the composition of gut microbiota through oral intake of prebiotics and probiotics may serve as a new effective adjuvant treatment measure for allergic diseases. In this paper, the main mechanism of food allergy based on intestinal immunity was described firstly. Then, the clinical and experimental evidence showed that different prebiotics and probiotics affect food allergy by changing the structure and composition of gut microbiota was summarized. Moreover, the molecular mechanism in which the gut microbiota and their metabolites may directly or indirectly regulate the immune system or intestinal epithelial barrier function to affect food immune tolerance of host were also reviewed to help in the development of food allergy prevention and treatment strategies based on prebiotics and probiotics.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Research Advances in the Treatment of Allergic Rhinitis by Probiotics

Allergic rhinitis (AR) impairs the quality of life of patients and reduces the efficiency of social work, it is an increasingly serious public medical and economic problem in the world. Conventional anti-allergic drugs for the treatment of allergic rhinitis (AR) can cause certain side effects, which limit the quality of life of patients. Therefore, it makes sense to look for other forms of treatment. Several studies in recent years have shown that probiotics have shown anti-allergic effects in various mouse and human studies. For example, the application of certain probiotic strains can effectively relieve the typical nasal and ocular symptoms of allergic rhinitis in children and adults, thereby improving the quality of life and work efficiency. At the same time, previous studies in humans and mice have found that probiotics can produce multiple effects, such as reduction of Th2 cell inflammatory factors and/or increase of Th1 cell inflammatory factors, changes in allergy-related immunoglobulins and cell migration, regulate Th1/Th2 balance or restore intestinal microbiota disturbance. For patients with limited activity or allergic rhinitis with more attacks and longer attack duration, oral probiotics have positive effects. The efficacy of probiotics in the prevention and treatment of allergic rhinitis is remarkable, but its specific mechanism needs further study. This review summarizes the research progress of probiotics in the treatment of allergic rhinitis in recent years.

Characteristics of the Gut Microbiota in Japanese Patients with Premenstrual Syndrome

Purpose

The present study aimed to characterize the gut microbiota of individuals with premenstrual syndrome.

Patients and Methods

The gut microbiota of 24 Japanese women with PMS (PMS group) and 144 healthy Japanese women (control group) were compared. Analysis of the α- and β-diversities and the gut microbial composition at the genus level were performed using 16S rRNA gene sequence data obtained from stool samples.

Results

A significant difference in age was observed between the PMS and control groups; however, no significant difference was observed in BMI. The α-diversity measured using the Simpson index was significantly higher in the PMS group than the control group. Visualization of the β-diversity using non-metric multidimensional scaling and permutational multivariate analysis of variance (PERMANOVA) showed that the distance of the gut microbiota between the PMS and control groups is significantly different. Furthermore, a significant difference in the composition of the gut microbiota was observed between the PMS and control groups. At the genus level, the abundances of Collinsella, Bifidobacterium, and Blautia were significantly higher in the PMS group than in the control group. In particular, the abundance of Collinsella in the PMS group was approximately 4.5 times higher than that in the control group. To rule out the confounding effect of age in the abundances of Bifidobacterium, Blautia, and Collinsella, the gut microbiota of the PMS and control groups were compared by age group. Results showed that Collinsella had the highest effect size in participants of 30–40 years of age (mean age: 36.39 ± 4.68 years).

Conclusion

These results suggest that the PMS group possesses a characteristic gut microbiota. In particular, Collinsella was strongly associated with PMS. Since Collinsella has been reported to be associated with diet, dietary interventions such as prebiotics targeting Collinsella may be effective in preventing, improving, and alleviating PMS.

Multi-omics analysis reveals gut microbiota-induced intramuscular fat deposition via regulating expression of lipogenesis-associated genes

The gut microbiome has great effects on the digestion, absorption, and metabolism of lipids. However, the microbiota composition that can alter the fat deposition and the meat quality of pigs remains unclear. Here, we used Laiwu (LW) pigs (a native Chinese breed with higher intramuscular fat) compared with commercial crossbreed Duroc × (Landrace × Yorkshire) (DLY) pigs to investigate the effects of microbiota on meat quality, especially in intramuscular fat content. A total of 32 DLY piglets were randomly allotted to 4 groups and transplanted with fecal microbiota from healthy LW pigs. The results indicated that the high dose of fecal microbiota transplantation (HFMT) selectively enhanced fat deposition in longissimus dorsi (P < 0.05) but decreased backfat thickness (P < 0.05) compared with control group. HFMT significantly altered meat color and increased feed conversation ratio (P < 0.05). Furthermore, the multi-omics analysis revealed that Bacteroides uniformis, Sphaerochaeta globosa, Hydrogenoanaerobacterium saccharovorans, and Pyramidobacter piscolens are the core species which can regulate lipid deposition. A total of 140 male SPF C57BL/6j mice were randomly allotted into 7 groups and administrated with these 4 microbes alone or consortium to validate the relationships between microbiota and lipid deposition. Inoculating the bacterial consortium into mice increased intramuscular fat content (P < 0.05) compared with control mice. Increased expressions of lipogenesis-associated genes including cluster of differentiation 36 (Cd36), diacylglycerol O-acyltransferase 2 (Dgat2), and fatty acid synthase (FASN) were observed in skeletal muscle in the mice with mixed bacteria compared with control mice. Together, our results suggest that the gut microbiota may play an important role in regulating the lipid deposition in the muscle of pigs and mice.

Probiotics: The Next Dietary Strategy against Brain Aging

Owing to their long history of safe use, probiotic microorganisms, typically from the genus Lactobacillus, have long been recognized, especially in traditional and fermented food industries. Although conventionally used for dairy, meat, and vegetable fermentation, the use of probiotics in health foods, supplements, and nutraceuticals has gradually increased. Over the past two decades, the importance of probiotics in improving gut health and immunity as well as alleviating metabolic diseases has been recognized. The new concept of a gut-heart-brain axis has led to the development of various innovations and strategies related to the introduction of probiotics in food and diet. Probiotics influence gut microbiota profiles, inflammation, and disorders and directly impact brain neurotransmitter pathways. As brain health often declines with age, the concept of probiotics being beneficial for the aging brain has also gained much momentum and emphasis in both research and product development. In this review, the concept of the aging brain, different in vivo aging models, and various aging-related benefits of probiotics are discussed.

Bifidobacterium lactis BL-99 protects mice with osteoporosis caused by colitis via gut inflammation and gut microbiota regulation

Patients diagnosed with inflammatory bowel disease or related conditions also frequently suffer from osteoporosis as a consequence of changes in the intestinal microenvironment and consequent dysbiosis. We hypothesized that anti-inflammatory probiotic treatment would be sufficient to alleviate intestinal inflammation and thereby prevent the development of osteoporosis. To that end, the ability of Bifidobacterium lactis BL-99 administration to protect against bone loss in an experimental model of dextran sodium sulfate-induced ulcerative colitis (UC) was analyzed, and the underlying molecular mechanisms were interrogated in detail. The results of these analyses revealed that BL-99 administration suppressed colitis-associated weight loss (P < 0.05), disease activity index scores, and the production of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-17) (P < 0.05). Colon tissue pathological sections similarly revealed BL-99-mediated reductions in tissue injury severity. Micro-computed tomography (Micro-CT) analyses further exhibited significant improvements in percent bone volume (BV/TV) as well as trabecular number and thickness in BL-99-treated animals (P < 0.05). Such probiotic supplementation also resulted in pronounced changes in the composition of the gut microbiota. Moreover, BL-99 intervention markedly increased the expression of intestinal barrier-related proteins (Claudin-1, MUC2, ZO-1, and Occludin). Together, these results suggest that BL-99 can be utilized as a beneficial probiotic preparation to prevent the incidence of osteoporosis in UC patients owing to its ability to shape the intestinal microflora and to suppress inflammatory cytokine production.

Berberine Relieves Metabolic Syndrome in Mice by Inhibiting Liver Inflammation Caused by a High-Fat Diet and Potential Association With Gut Microbiota

Whether berberine mediates its anti-inflammatory and blood sugar and lipid-lowering effects solely by adjusting the structure of the gut microbiota or by first directly regulating the expression of host pro-inflammatory proteins and activation of macrophages and subsequently acting on gut microbiota, is currently unclear. To clarify the mechanism of berberine-mediated regulation of metabolism, we constructed an obese mouse model using SPF-grade C57BL/6J male mice and conducted a systematic study of liver tissue pathology, inflammatory factor expression, and gut microbiota structure. We screened the gut microbiota targets of berberine and showed that the molecular mechanism of berberine-mediated treatment of metabolic syndrome involves the regulation of gut microbiota structure and the expression of inflammatory factors. Our results revealed that a high-fat diet (HFD) significantly changed mice gut microbiota, thereby probably increasing the level of toxins in the intestine, and triggered the host inflammatory response. The HFD also reduced the proportion of short-chain fatty acid (SCFA)-producing genes, thereby hindering mucosal immunity and cell nutrition, and increased the host inflammatory response and liver fat metabolism disorders. Further, berberine could improve the chronic HFD-induced inflammatory metabolic syndrome to some extent and effectively improved the metabolism of high-fat foods in mice, which correlated with the gut microbiota composition. Taken together, our study may improve our understanding of host-microbe interactions during the treatment of metabolic diseases and provide useful insights into the action mechanism of berberine.

Effect of Lactiplantibacillus plantarum HM-22 on immunoregulation and intestinal microbiota in α-lactalbumin-induced allergic mice

Milk protein is one of the eight major allergens, and α-lactalbumin (α-LA) is one of the major allergens of bovine milk protein. Our previous studies found that Lactiplantibacillus plantarum HM-22 (L. plantarum HM-22) showed a good gastrointestinal survival rate and intestinal colonization. To investigate the effect of L. plantarum HM-22 on intestinal inflammation and intestinal microbiota in α-LA-induced allergic mice, in this study, L. plantarum HM-22 at low and high doses was intragastrically administered to α-LA-induced allergic mice for 5 weeks. The results showed that L. plantarum HM-22 significantly relieved the weight loss and organ index of α-LA-induced allergic mice (p < 0.05). L. plantarum HM-22 increased the levels of interleukin-10 (IL-10), interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) in the serum of α-LA-induced allergic mice and decreased the levels of total immunoglobulin E (IgE) and the proinflammatory factor interleukin-4 (IL-4) (p < 0.05). The crypt structure of the colon tissues of α-LA-induced allergic mice changed, goblet cells decreased, and the phenomenon of a large number of inflammatory corpuscles that appeared was improved and alleviated with the intervention of L. plantarum HM-22 by hematoxylin-eosin (HE) staining. Western blot analysis showed that L. plantarum HM-22 significantly increased the expression of occludin and claudin-1 in the colon of α-LA-induced allergic mice and decreased the expression of the inflammatory proteins p65 and IκBα (p < 0.05). The intestinal microbiota of mice in each group was determined by 16S rRNA amplicon sequencing, and the results showed that intervention with L. plantarum HM-22 improved the intestinal microbes of α-LA-induced allergic mice. Spearman's correlation analysis revealed the correlation between intestinal microbiota changes and the α-LA-induced allergy-related index. This study provides a theoretical basis for probiotics to prevent allergies by changing the intestinal microbiota.

Colonization Ability and Impact on Human Gut Microbiota of Foodborne Microbes From Traditional or Probiotic-Added Fermented Foods: A Systematic Review

A large subset of fermented foods act as vehicles of live environmental microbes, which often contribute food quality assets to the overall diet, such as health-associated microbial metabolites. Foodborne microorganisms also carry the potential to interact with the human gut microbiome via the food chain. However, scientific results describing the microbial flow connecting such different microbiomes as well as their impact on human health, are still fragmented. The aim of this systematic review is to provide a knowledge-base about the scientific literature addressing the connection between foodborne and gut microbiomes, as well as to identify gaps where more research is needed to clarify and map gut microorganisms originating from fermented foods, either traditional or added with probiotics, their possible impact on human gut microbiota composition and to which extent foodborne microbes might be able to colonize the gut environment. An additional aim was also to highlight experimental approaches and study designs which could be better standardized to improve comparative analysis of published datasets. Overall, the results presented in this systematic review suggest that a complex interplay between food and gut microbiota is indeed occurring, although the possible mechanisms for this interaction, as well as how it can impact human health, still remain a puzzling picture. Further research employing standardized and trans-disciplinary approaches aimed at understanding how fermented foods can be tailored to positively influence human gut microbiota and, in turn, host health, are therefore of pivotal importance.

The Association Between Intestinal Bacteria and Allergic Diseases-Cause or Consequence?

The incidence of allergic disorders has been increasing over the past few decades, especially in industrialized countries. Allergies can affect people of any age. The pathogenesis of allergic diseases is complex and involves genetic, epigenetic, and environmental factors, and the response to medication is very variable. For some patients, avoidance is the sole effective therapy, and only when the triggers are identifiable. In recent years, the intestinal microbiota has emerged as a significant contributor to the development of allergic diseases. However, the precise mechanisms related to the effects of the microbiome on the pathogenesis of allergic diseases are unknown. This review summarizes the recent association between allergic disorders and intestinal bacterial dysbiosis, describes the function of gut microbes in allergic disease development from both preclinical and clinical studies, discusses the factors that influence gut microbial diversity and advanced techniques used in microbial analysis. Ultimately, more studies are required to define the host-microbial relationship relevant to allergic disorders and amenable to new therapeutic interventions.

Streptococcus thermophilus MN-ZLW-002 Can Inhibit Pre-adipocyte Differentiation through Macrophage Activation

It is well documented that obesity and metabolic syndrome have a deep association with the intestinal immune system of the host animal. Recent studies indicate that some selected probiotics can modulate the immune responses of the host animal, thereby altering its lipid metabolism. However, the underlying mechanisms are still not fully understood. This study was conducted to investigate the possibility of probiotics to activate macrophages in the hosts, thus alter the differentiation of pre-adipocytes. In this study, Streptococcus thermophilus MN-ZLW-002 (MN-ZLW-002) was co-cultured with RAW264.7 macrophages, with Lactobacillus rhamnosus GG (LGG) as a control. The conditioned medium (CM) of the co-culture was collected and then added to 3T3-L1 pre-adipocytes. Viable and heat-killed (80 °C, 30 min) MN-ZLW-002 stimulated RAW264.7 cells to produce significant amounts of interleukin (IL)-6 and tumor necrosis factor (TNF)-α and induced intense phosphorylation of P38, p44/42 mitogen-activated protein kinase (MAPK) (extracellular signal-regulated kinase (ERK)) and nuclear factor κB (NF-κB). Cytokine production reduced dramatically when heat-killed MN-ZLW-002 was treated with Ribonuclease. Viable and heat-killed LGG induced less cytokine production and little signaling protein activation. Viable and heat-killed MN-ZLW-002-stimulated RAW264.7-CM notably suppressed pre-adipocytes differentiation. However, viable LGG-stimulated RAW264.7-CM had a weaker effect and heat-killed LGG-stimulated RAW264.7-CM had no effect. These findings suggest that viable and heat-killed (80 °C, 30 min) MN-ZLW-002 may alter its lipid metabolism by regulating its immune response, possibly via the release of cytokine, particularly TNF-α. The RNA of heat-killed MN-ZLW-002 may be a key component in its immune activation effect.

Short-Term Lincomycin Exposure Depletion of Murine Microbiota Affects Short-Chain Fatty Acids and Intestinal Morphology and Immunity

Lincomycin, as one of the most commonly used antibiotics, may cause intestinal injury, enteritis and other side effects, but it remains unknown whether these effects are associated with microbial changes and the effects of different doses of lincomycin on infants. Here, 21-day old mice were exposed to 1 and 5 g/L lincomycin to explore the effects of lincomycin on the gut microbiota, metabolites and inflammation. Compared to the control mice, 1 g/L lincomycin exposure decreased the body weight gain of mice (p < 0.05). Both 1 and 5 g/L lincomycin exposure reduced the diversity and microbial composition of mice (p < 0.05). Furthermore, 1 and 5 g/L lincomycin reduced the relative concentrations of acetate, propionate, butyrate, valerate, isobutyric acid and isovaleric acid in the colon chyme of mice (p < 0.05). In addition, 5 g/L lincomycin exposure reduced the villus height, crypt depth, and relative expression of TLR2, TLR3, TLR4, IL-18, TNF-α, and p65 in the jejunum of mice (p < 0.05), while 1 g/L lincomycin exposure reduced the relative expression of TLR2, TLR3, TNF-α, and p65 (p < 0.05). Collectively, these results highlight the depletion effect of short-term lincomycin exposure on microbiota and the further regulatory effect on intestinal morphology and immunosuppression in infant mice.

Anti-adipogenesis and metabolism-regulating effects of heat-inactivated Streptococcus thermophilus MN-ZLW-002

Metabolic syndrome and obesity have become serious threats to public health worldwide. This study was conducted to evaluate the anti-adipogenesis and metabolism-regulating effects of heat-inactivated Streptococcus thermophilus MN-ZLW-002 (MN-ZLW-002), which can be used as a yogurt starter. In vitro study suggested that MN-ZLW-002 stimulated the RAW264.7 macrophages to produce significant amounts of interleukin (IL)-6, IL-10 and tumour necrosis factor (TNF)-α and induced intense phosphorylation of P38, p44/42 MAPK and nuclear factor κB. MN-ZLW-002-stimulated RAW264.7-conditioned medium (CM) notably suppressed the differentiation and adipogenesis of 3T3-L1 pre-adipocytes. The 12-week in vivo study suggested that orally administered MN-ZLW-002 significantly reduced the weight gain of mice caused by the high-fat diet (HFD) at weeks 3-8; decreased fasting blood glucose levels at week 4 and week 8; decreased serum total triglyceride level at week 12. MN-ZLW-002 also reduced serum IL-1β and chemokine ligand 3 levels in the HFD-fed mice. These findings suggest that heat-inactivated MN-ZLW-002 can suppress adipocytes differentiation and lipid accumulation by regulating the immune response, possibly via the release of cytokines, particularly TNF-α; MN-ZLW-002 can improve metabolism-related indicators in the early stage of HFD intervention and regulate the related pro-inflammatory immune response.

The role of probiotics on the roadmap to a healthy microbiota: a symposium report

The ninth International Yakult Symposium was held in Ghent, Belgium in April 2018. Keynote lectures were from Professor Wijmenga on using biobanks to understand the relationship between the gut microbiota and health; and Professor Hill on phage-probiotic interactions. Session one included talks from Professor Plӧsch on epigenetic programming by nutritional and environmental factors; Professor Wilmes on the use of "omics" methodologies in microbiome research and Professor Rescigno on the gut vascular barrier. Session two explored the evidence behind Lactobacillus casei Shirota with Dr Nanno explaining the plasticity in immunomodulation that enables the strain to balance immune functions; Dr Macnaughtan outlining its potential therapeutic use in cirrhosis and Professor Nishida detailing effects in subjects under stress. The third session saw Professor Marchesi describing that both the host genes and the gut microbiota can play a role in cancer; Professor Bergheim highlighting crosstalk between the gut and the liver and Professor Cani describing the relationship between the gut microbiota and the endocrine system. The final session explored probiotic mechanisms, with Professor Lebeer dissecting the challenges in conducting mechanistic studies; Professor Wehkamp describing the mucosal defence system and Professor Van de Wiele detailing methods for modelling the gut microbiota in vitro.

In situ spectroscopic analysis of Lactobacillus rhamnosus GG flow on an abiotic surface reveals a role for nutrients in biofilm development

In this work, infrared spectroscopy was used to monitor the changes in the biochemical composition of biofilms of the probiotic bacterium Lactobacillus rhamnosus GG (LGG) in three nutritive media (10-fold diluted MRS, AOAC, and mTSB), in situ and under flow conditions. Epifluorescence microscopy was used to observe the shape of LGG cells and their distribution on the surface. Spectroscopic fingerprints recorded as a function of time revealed a medium-dependent content of nucleic acids, phospholipids and polysaccharides in the biofilms. In addition, time-dependent synthesis of lactic acid was observed in MRS/10 and AOAC/10. Polysaccharides were produced to the highest extent in mTSB/10, and the biofilms obtained were the densest in this medium. The rod shape of the cells was preserved in MRS/10, whereas acidic stress induced in AOAC/10 and the nutritional quality of mTSB/10 led to strong morphological changes. These alterations due to the nutritive environment are important to consider in research and use of LGG biofilms.

Loading ceftriaxone, vancomycin, and Bifidobacteria bifidum TMC3115 to neonatal mice could differently and consequently affect intestinal microbiota and immunity in adulthood

Recent studies have demonstrated that antibiotics/or probiotics administration in early life play key roles on modulating intestinal microbiota and the alterations might cause long-lasting consequences both physiologically and immunologically. We investigated the effects of early life ceftriaxone, vancomycin and Bifidobacterium bifidum TMC3115 (TMC3115) treatment on intestinal microbiota and immunity both in neonates and adults even after termination of antibiotics exposure. We found that ceftriaxone and vancomycin, but not TMC3115, significantly altered the intestinal microbiota, serum total IgE level, and the morphology and function of the intestinal epithelium in the neonatal mice. In the adult stages, the diversity and composition of the intestinal microbiota were significantly different in the antibiotic-treated mice, and ceftriaxone-treated mice exhibited significantly higher serum total IgE and OVA-specific IgE levels. TMC3115 significantly mitigated the alteration of intestinal microbiota caused by ceftriaxone not vancomycin. Antibiotics and TMC3115 can differently modulate intestinal microbiota and SCFAs metabolism, affecting the development and function of the immunity and intestinal epithelium to different degrees in neonatal mice. Neonatal ceftriaxone-induced abnormal intestinal microbiota, immunity and epithelium could last to adulthood partly, which might be associated with the enhancement of host susceptibility to IgE-mediated allergies and related immune responses, TMC3115 may protect against the side effects of antibiotic treatment, at least partly.

Changes in intestinal microbiota of Bufo gargarizans and its association with body weight during metamorphosis

The assembly of intestinal microbial communities can play major roles in animal development. We hypothesized that intestinal microbial communities could mirror the developmental programs of amphibian metamorphosis. Here, we surveyed the morphological parameters of the body and intestine of Bufo gargarizans at varying developmental stages and inventoried the intestinal microbial communities of B. gargarizans at four key developmental stages via 16S rDNA gene sequencing. Firstly, our survey showed that during metamorphosis, body weight and intestinal weight were reduced by 56.8 and 91.8%, respectively. Secondly, the gut bacterial diversity of B. gargarizans decreased with metamorphosis and the composition of the tadpoles' intestinal microbiota varied across metamorphosis. Compared to aquatic larvae, terrestrial juveniles showed major shifts in microbial composition, including reduction in Proteobacteria and Actinobacteria, increases in Bacteroidetes and Fusobacteria, and the appearance of Verrucomicrobia. Firmicutes in four developmental stages showed similar abundance at the phylum level, but in each stage was driven by distinct genera. Enterobacter, Aeromonas, Mucinivorans and Bacteroides also changed in abundance and were found to be significantly correlated with loss of body or intestinal tissue during metamorphosis. These results indicate a shift in intestinal microbial community composition throughout amphibian metamorphosis.

Possible correlation between gut microbiota and immunity among healthy middle-aged and elderly people in southwest China

BACKGROUND

The present study was conducted to investigate the possible association between gut microbes and immunity among healthy middle-aged and elderly individuals in southwest China. A total of 148 healthy adults aged ≥ 50 years were divided into two age groups: middle-aged group (50-59 years; n = 67, 54.13 ± 3.32) and elderly group (≥ 60 years; n = 81, 64.70 ± 3.93). Blood samples were collected to measure serum immune and biochemical indices. Gut microbiota compositions of the groups were characterized on the basis of faecal DNA using 16S rRNA gene sequencing.

RESULTS

Among the detected gut microbes, the presence of Alistipes was negatively correlated with age in both groups. In the middle-aged group, age was negatively correlated with the presence of Desulfovibrio and Faecalibacterium. In the elderly group, Coprococcus was present at significantly higher levels; age was negatively correlated with the presence of Lachnobacterium, Oxalobacter and the Chao index, whereas positively correlated with the presence of Sutterella. In the middle-aged group, the presence of Bacteroidetes was positively correlated with serum immunoglobulin G (IgG) levels and the percent of CD8+ T cells and negatively correlated with the CD4+/CD8+ ratio; the presence of Firmicutes was negatively correlated with IgM levels; Bacteroidetes/Firmicutes ratio was positively correlated with IgG and IgM levels and Simpson index was negatively correlated with the percent of CD8+ T cells and positively correlated with CD4+/CD8+ ratio. In the elderly group, the presence of Verrucomicrobia (identified as genus Akkermansia) was positively correlated with IgA levels and the percent of CD8+ T cells and negatively correlated with the percent of CD4+ T cells and CD4+/CD8+ ratio; the Chao index and observed species were positively correlated with IgA levels.

CONCLUSIONS

These results indicated that ageing could significantly correlate with the composition of gut microbiota in terms of quantity and quality. Changes in gut microbiota caused by ageing, characterized by decreased Bacteroidetes levels, might be associated with immunosenescence among healthy middle-aged and elderly people in southwest China.

The distinct effects of orally administered Lactobacillus rhamnosus GG and Lactococcus lactis subsp. lactis C59 on gene expression in the murine small intestine

The molecular mechanisms of strain-specific probiotic effects and the impact of the oral administration of probiotic strains on the host’s gene expression are not yet well understood. The aim of this study was to investigate the strain-specific effects of probiotic strain intake on gene expression in the murine small intestine. Two distinct strains of lactic acid bacteria, Lactobacillus rhamnosus GG (GG) and Lactococcus lactis subsp. lactis C59 (C59), were orally administered to BALB/c mice, daily for 2 weeks. The total RNA was isolated from the upper (including the duodenum) and lower (the terminal ileum) small intestine, and gene expression was assessed by microarray analysis. The data revealed (1) oral administration of C59 and GG markedly down-regulated the expression of genes encoding fibrinogen subunits and plasminogen in the upper small intestine; (2) administration of more than 1 × 10⁷ CFU/day of GG changed the gene expression of the host ileum. (3) strain- and dose-related effects on various GO biological processes; and (4) enrichment for B cell-related Gene Ontology terms among up-regulated genes in the terminal ileum of mice administered the 1 × 10⁹ CFU/day of GG. The distinct effects of GG and C59 on gene expression in the intact small intestine provide clues to understand how the health beneficial effects of specific strains of probiotic bacteria are mediated by interactions with intestinal cells.