[Microbiota and enteral nutrition]

Effects of Atractylodes lancea extracts on intestinal flora and serum metabolites in mice with intestinal dysbacteriosis

OBJECTIVE

This study aims to explore the effect of an extract of Atractylodes lancea (A. lancea) on antibiotics-induced intestinal tract disorder and the probable therapeutic mechanisms employed by this extract to ameliorate these disorders.

METHODS

Three days after acclimatization, nine male and nine female specific-pathogen-free (SPF) mice were randomly assigned into three groups: Group C (normal saline), Group M (antibiotic: cefradine + gentamicin), and Group T (antibiotic + A. lancea extract). Each mouse in Groups M and T received intragastric (i.g.) gavage antibiotics containing cefradine and gentamicin sulfate (0.02 ml/g^-1/D^-1) for 7 days. A. lancea extract (0.02 ml/g^-1/D^-1) was administered by i.g. gavage to Group T mice for 7 days following the cessation of antibiotic therapy. Group M received an equivalent volume of normal saline for 7 days, while Group C received an equivalent volume of normal saline for 14 days. Afterwards, we collected mouse feces to assess changes in intestinal microbiota by 16S ribosomal ribonucleic acid (rRNA) sequencing and metabolomics. In addition, serum samples were gathered and analyzed using liquid chromatography-mass spectrometry (LS-MS). Finally, we performed a correlation analysis between intestinal microbiota and metabolites.

RESULTS

After treatment with antibiotic, the richness and diversity of the flora, numbers of wall-breaking bacteria and Bacteroidetes, and the numbers of beneficial bacteria decreased, while the numbers of harmful bacteria increased. After i.g. administration of A. lancea extract, the imbalance of microbial flora began to recover. Antibiotics primarily influence the metabolism of lipids, steroids, peptides, organic acids, and carbohydrates, with lipid compounds ranking first. Arachidonic acid (AA), arginine, and proline have relatively strong effects on the metabolisms of antibiotic-stressed mice. Our findings revealed that A. lancea extract might restore the metabolism of AA and L-methionine. The content of differential metabolites detected in the serum of Group T mice was comparable to that in the serum of Group C mice, but significantly different from that of Group M mice. Compared to putative biomarkers in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, it was found that altered metabolites, such as amino acids, glycerol, and phospholipids, were primarily associated with the metabolism.

CONCLUSIONS

The effective mechanisms of A. lancea extract in regulating the disorder of intestinal flora in mice are related to the mechanisms of A. lancea. It could relate to lipid metabolism, bile acid metabolism, and amino acid metabolism. These results will provide a basis for further explaining the mechanism by which A. lancea regulats intestinal flora.

Gut microbiome alterations in ICU patients with enteral nutrition-related diarrhea

Enteral Nutrition-related Diarrhea (END) is an extremely common complication in Intensive Care Unit (ICU) patients. However, it is currently unclear whether the patient’s gut microbiota is disturbed. Our study aimed to explore the characteristics of gut microbiota changes in END patients. We divided ICU patients into no-END group (n = 7) and END group (n = 7) according to whether they had END, then stool samples were collected separately. The V3-V4 region of stool bacterial 16S rRNA gene was amplified by PCR and sequenced on an Illumina MiSeq PE300 platform. Microbiome data obtained by quality control were analyzed, including microbial community composition, diversity and gene function prediction.The results showed that the dominant gut microbiota in ICU patients who were given total enteral nutrition were Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Verrucomicrobia. Bacterial richness and diversity in END patients were all significantly lower than those in no-END patients. In addition, END caused significant changes in bacterial composition. LEfSe found 34 biomarkers represented by Bacteroidetes and Subdoligranulum in the no-END group as well as 11 biomarkers represented by Enterococcus and Klebsiella in the END group. Finally, through PICRUST function prediction, we found that diarrhea led to abnormal changes in numerous KEGG pathways mainly related to immunity and metabolism. In short, ICU patients with END have severe gut dysbiosis, and our study provides a reliable experimental basis for the patient’s microbiota therapy.

Association between iron supplementation and the presence of diarrhoea in Peruvian children aged 6-59 months: analysis of the database of the Demographic and Family Health Survey in Peru (DHS, Peru), years 2009-2019

INTRODUCTION

According to the WHO, anaemia is a severe public health problem when the prevalence is ≥ 40 %. In 2019, in Peru, 40·1 % of children (aged 6 to 35 months) are diagnosed as anaemic. This is a concern since, despite the efforts of the governments to reduce the prevalence, the problem has stagnated since 2011. The treatment applied to deal with anaemia is Fe supplementation. Although Fe is essential for cell function, an excess can produce adverse responses, such as gut inflammation affecting microbiota and resulting in diarrhoeic episodes.

OBJECTIVE

To determine the association between diarrhoea and Fe supplementation in children with and without anaemia, controlling for different socio-demographic variables.

DESIGN

We conducted via logistic regression to obtain diarrhoea prevalence ratios (PR), adjusted by age, sex, geographic region, water and sanitation service, and rurality. The survey asked for recent episodes of diarrhoea during the last 7 d; similarly, after the consumption of Fe supplements during the last 12 months before the survey.

SETTING

Peru.

PARTICIPANTS

The Demographic and Family Health Survey (DHS) is conducted annually at home among 14 202 children on average (2009-2019).

RESULTS

Fe supplementation in the last 7 d (PR = 1·09) or the last 12 months (PR = 1·19) (P < 0·0001) was associated with an increased risk of diarrhoea. The same association was observed between Fe supplementation and the presence of anaemia.

CONCLUSIONS

Fe supplementation is associated with diarrhoea and overuse in children should be avoided.

Effects of a Synbiotic Formula on Functional Bowel Disorders and Gut Microbiota Profile during Long-Term Home Enteral Nutrition (LTHEN): A Pilot Study

Long-term enteral nutrition (LTEN) can induce gut microbiota (GM) dysbiosis and gastrointestinal related symptoms, such as constipation or diarrhoea. To date, the treatment of constipation is based on the use of laxatives and prebiotics. Only recently have probiotics and synbiotics been considered, the latter modulating the GM and regulating intestinal functions. This randomized open-label intervention study evaluated the effects of synbiotic treatment on the GM profile, its functional activity and on intestinal functions in long-term home EN (LTHEN) patients. Twenty LTHEN patients were recruited to take enteral formula plus one sachet/day of synbiotic (intervention group, IG) or enteral formula (control group, CG) for four months and evaluated for constipation, stool consistency, and GM and metabolite profiles. In IG patients, statistically significant reduction of constipation and increase of stool consistency were observed after four months (T₁), compared to CG subjects. GM ecology analyses revealed a decrease in the microbial diversity of both IC and CG groups. Biodiversity increased at T₁ for 5/11 IG patients and Methanobrevibacter was identified as the biomarker correlated to the richness increase. Moreover, the increase of short chain fatty acids and the reduction of harmful molecules have been correlated to synbiotic administration. Synbiotics improve constipation symptoms and influences Methanobrevibacter growth in LTHEN patients.

Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment

Probiotics are commonly prescribed as an adjuvant in the treatment of antibiotic-associated diarrhea caused by Clostridium difficile. We report the case of an immunocompromised 73-year-old patient on chemotherapy who developed Saccharomyces cerevisiae var. boulardii fungemia in a central venous catheter during treatment of antibiotic-associated pseudomembranous colitis with the probiotic Saccharomyces cerevisiae var. boulardii. Fungemia was resolved after interruption of probiotic administration without the need to replace the central venous line.

Saccharomyces boulardii CNCM I-745 supports regeneration of the intestinal microbiota after diarrheic dysbiosis - a review

The probiotic medicinal yeast Saccharomyces cerevisiae HANSEN CBS 5926 (Saccharomyces boulardii CNCM I-745) is used for the prevention and treatment of diarrhea. Its action is based on multiple mechanisms, including immunological effects, pathogen-binding and antitoxinic effects, as well as effects on digestive enzymes. Correlated with these effects, but also due to its inherent properties, S. boulardii is able to create a favorable growth environment for the beneficial intestinal microbiota, while constituting extra protection to the host mucus layer and mucosa. This review focuses on the positive influence of S. boulardii on the composition of the intestinal microbiota. In a dysbiosis, as during diarrhea, the main microbial population (especially Lachnospiraceae, Ruminococcaceae, Bacteroidaceae, and Prevotellaceae) is known to collapse by at least one order of magnitude. This gap generally leads to transient increases in pioneer-type bacteria (Enterobacteriaceae, Bifidobacteriaceae, and Clostridiaceae). Several human studies as well as animal models demonstrate that treatment with S. boulardii in dysbiosis leads to the faster reestablishment of a healthy microbiome. The most relevant effects of S. boulardii on the fecal composition include an increase of short chain fatty acid-producing bacteria (along with a rise in short chain fatty acids), especially of Lachnospiraceae and Ruminococcaceae, as well as an increase in Bacteroidaceae and Prevotellaceae. At the same time, there is a suppression of pioneer bacteria. The previously observed preventive action of S. boulardii, eg, during antibiotic therapy or regarding traveler’s diarrhea, can be explained by several mechanisms, including a stabilizing effect on the healthy microbiota as well as possibly on the mucus layer. Several different dysbiotic situations could profit from the effects of S. boulardii CNCM I-745. Its additional potential lies in a general stabilization of the gut flora for at-risk populations. More studies are needed to explore the full potential of this versatile probiotic yeast.

Preventing diarrhoea in enteral nutrition: the impact of the delivery set hang time

BACKGROUND

To meet the current recommendations for enteral tube feeding (ETF), we updated our previous practice in 2011 and began to use a 24-h delivery set hang time (DSHT). We evaluated the impact of this update on the risk of diarrhoea and in diarrhoea-free survival.

METHODS

Observational, retrospective study with historical controls on ischaemic and haemorrhagic stroke patients undergoing ETF. Diarrhoea occurrence (≥ 3 liquid stools in 24 h) was compared between patients with a 24 h DSHT (2011-2014) and a 72/96 h DSHT (2010-2011). The analysis was conducted using Kaplan-Meier curves and a Cox regression model.

RESULTS

A total of 175 patients were included [median age 81 years (IQR = 12), 46.9% males], 103 in the group with a 24 h DSHT and 72 in the group with a 72/96 h DSHT. The group with a 24 h DSHT had a lower diarrhoea frequency (13.6% vs. 34.7%, risk ratio: 0.39, 95% CI: 0.22-0.70, p = 0.001) and a lower diarrhoea incidence rate (0.87 vs. 2.32 cases of diarrhoea/100 patient*day, rate ratio: 0.37, 95% CI: 0.19-0.72, p = 0.004). The Kaplan-Meier curves showed a longer diarrhoea-free survival for this group (p = 0.003, log-rank test). A 24 h DSHT was associated with a lower risk of diarrhoea (HR = 0.27, 95% CI: 0.12-0.61, p = 0.002), adjusted by albumin, stroke severity, intravenous thrombolysis, the administration of clindamycin and cefotaxime, and the administration of an enteral formula for diabetic patients.

CONCLUSIONS

The 24 h DSHT was independently associated with a lower risk of diarrhoea and longer diarrhoea-free survival in hospitalised patients with acute stroke under ETF, compared with a 72/96 h DSHT.

A critical appraisal of probiotics (as drugs or food supplements) in gastrointestinal diseases

Probiotics may be registered as food supplements or drugs. This article summarizes differences in European regulations of probiotics registered as food supplements and drugs, as well as issues related to the quality of probiotic products. For registration as a drug, the European Medicines Agency demands extensive and detailed quality, efficacy and safety evidence; whereas compulsory analyses requested for food supplements consist only in a nutritional analysis. As a result, the quality of those probiotics registered as drugs, compared to food supplements, is in general controlled with higher standards. Despite these differences and whatever the status of the probiotic product, its efficacy and safety has to be documented in well conducted randomized controlled trials (RCTs). Furthermore, this paper reviews recent evidence on the use of probiotics for gastrointestinal diseases, evaluating all the existing information up to January 2014. In all eligible published studies in which use of probiotics for gastrointestinal diseases were investigated and reported, no language limitations were applied. Special focus is placed on RCTs (or their meta-analyses) showing positive results, so that the findings may be applicable to everyday clinical practice. Currently, the best documented clinical areas appear to be probiotics efficacy for the treatment of acute gastroenteritis in children and for the prevention of antibiotic-associated diarrhea both in children and in adults. In other gastrointestinal conditions, some promising observations are emerging, but no definitive conclusions can be reached at present.

Mechanisms, prevention, and management of diarrhea in enteral nutrition

PURPOSE OF REVIEW

Diarrhea is a common and problematic complication of enteral nutrition, about which there has been considerable recent research. This article briefly reviews the mechanisms of diarrhea during enteral nutrition and then critically appraises the recent and emerging evidence for the prevention and management of this distressing complication.

RECENT FINDINGS

For many years, fiber was extensively investigated for its role in preventing diarrhea; however, a more recent focus has been the investigation of specific fiber blends, including soluble fibers and prebiotics, for which there is now considerable quality evidence. Enteral nutrition may result in deleterious effects on the gastrointestinal microbiota, including reductions in bifidobacteria and key butyrate producers. Their modulation by prebiotics has been confirmed in studies on healthy individuals, but convincing evidence in acutely ill patients is required. Probiotics have undergone extensive recent research and their effect on preventing diarrhea in enteral nutrition would seemingly be strain dependent. Further research is required on systematic approaches to treating diarrhea during enteral nutrition.

SUMMARY

A number of factors contribute to the pathogenesis of diarrhea in enteral nutrition, meaning that approaches to its prevention and management are necessarily multifaceted. Approaches to prevent diarrhea during enteral nutrition, and a clinical algorithm to manage it, are now presented.