Probiotics, critical illness, and methodologic bias

Effects of Probiotics in Conditions or Infections Similar to COVID-19 on Health Outcomes: An Evidence Analysis Center Scoping Review

Probiotics have been suggested as a potential intervention for improving outcomes, particularly ventilatory-associated pneumonia, in patients infected with coronavirus disease 2019 (COVID-19). However, with the rapid development of the COVID-19 pandemic, there is little direct evidence available in infected patients. The objective of this scoping review is to examine the availability and nature of literature describing the effect of probiotics in adults with conditions or infections similar to COVID-19 infection on related health outcomes. MEDLINE, Cumulative Index to Nursing & Allied Health Literature, and Cochrane Databases were searched for studies published from 1999 to May 1, 2020, examining the effect of probiotics in conditions applicable to individuals infected with COVID-19, including, but not limited to, other forms of coronavirus, critical illness, and mechanical ventilation. The databases search identified 1925 unique articles, 77 full-text articles were reviewed, and 48 studies were included in this scoping review, including 31 primary studies and 17 systematic reviews. Primary studies examined a range of interventions that varied by probiotic diversity and types, including 8 studies that focused on synbiotics, which include both pre- and probiotics. Several systematic reviews examined the effect of probiotics on ventilator-associated pneumonia and other infections. Although most systematic reviews concluded probiotics may improve these outcomes, most systematic review authors concluded that the evidence was low in quality and high in heterogeneity. In the absence of direct evidence with patients infected with COVID-19, studies in comparable populations are currently the best resource to guide probiotics interventions in conjunction with clinical expertise and multidisciplinary health care planning.

Weight gain by gut microbiota manipulation in productive animals

Antibiotics, prebiotics and probiotics are widely used as growth promoters in agriculture. In the 1940s, use of Streptomyces aureofaciens probiotics resulted in weight gain in animals, which led to the discovery of chlortetracycline. Tetracyclines, macrolides, avoparcin and penicillins have been commonly used in livestock agriculture to promote growth through increased food intake, weight gain, and improved herd health. Prebiotic supplements including oligosaccharides, fructooligosaccharides, and galactosyl-lactose improve the growth performance of animals. Probiotics used in animal feed are mainly bacterial strains of Gram-positive bacteria and have been effectively used for weight gain in chickens, pigs, ruminants and in aquaculture. Antibiotics, prebiotics and probiotics all modify the gut microbiota and the effect of a probiotic species on the digestive flora is probably determined by bacteriocin production. Regulations governing the introduction of novel probiotics and prebiotics vary by geographical region and bias is very common in industry-funded studies. Probiotic and prebiotic foods have been consumed for centuries, either as natural components of food, or as fermented foods and it is possible to cause the same weight gain effects in humans as in animals. This review presents the use of growth promoters in food-producing animals to influence food intake and weight gain.

Effects of probiotics in treatment of severe acute pancreatitis

AIM: To investigate the effects of probiotics in the treatment of severe acute pancreatitis (SAP).

METHODS: Thirty-nine SAP patients were randomly divided into two groups: a control group and a treatment group. The treatment group was given probiotics through the nasointestinal feeding tube, and the control group was given placebo (starch preparations). Infectious complications (including infected necrosis of the pancreas, pneumonia, urosepsis and bacteraemia), duration of intensive care, and rates of percutaneous drainage, intestinal ischemia and necrosis were compared between the two groups.

RESULTS: There was no significant difference (P > 0.05) in infectious complications, duration of intensive care or the rate of percutaneous drainage between the two groups, but the rate of intestinal ischemia and necrosis was significantly higher in the treatment group than in the control group.

CONCLUSION: Using probiotics does not reduce infectious complications, shorten the duration of intensive care, or reduce the rate of percutaneous drainage in patients with SAP, but increase the rate of intestinal ischemia and necrosis.

Comparative study of Kefir yogurt-drink and sodium fluoride mouth rinse on salivary mutans streptococci

AIM

The level of mutans streptococci (MS) is reduced by regularly consumption of probiotic Kefir drink. The present study aiming at answer to this question 'may the Kefir drink be considered an alternative to fluoride rinse?'

MATERIALS AND METHODS

Twenty-two healthy volunteers aged 22-32 years with good oral hygiene participated in this study. None of participants had received any antibiotic or antimicrobial agent or professional fluoride therapy within the last month. None of them exhibited active caries lesions. Smokers and subjects who have chewing gums xylitol habit or who were undergoing orthodontic treatment were excluded. In a cross over design with 2 parallel groups, people in group A for 2 weeks received 100 ml of Kefir drink per day, then avoided brushing, eating and drinking for an hour. Simultaneously, people in group B were administered 0.05% sodium fluoride rinse in the same manner. After washout period, people in groups A and B respectively used 0.05% sodium fluoride rinse and Kefir drink. Saliva sampling was performed before and after interventions. The acidity and the count of MS were assessed and data were analyzed statistically.

RESULT

There was no significant difference between base line pH values of saliva in study groups (p > 0.05). Although, a significant difference was shown between MS counts before and after interventions (p ≤ 0.0001 and p ≤ 0.0001 for NaF and Kefir respectively), but the equal inhibitory effect was found between study groups (p > 0.05).

CONCLUSION

Kefir drink can inhibit salivary MS as well the sodium fluoride rinse. This beverage may be considered an alternative for fluoride rinse. Clinical significance: Probiotics containing dairy products was known with anticariogenic properties. These agents may be used in caries control strategies adjunctively.

Probiotics for prevention of nosocomial infections: efficacy and adverse effects

PURPOSE OF REVIEW

In this era of increasing antimicrobial resistance, use of probiotics in infection prevention has brought new perspective. However, in 2008 the, until then considered, safe use of probiotics became an important topic after publication of a trial showing excess mortality in patients on probiotic prophylaxis. In this article, we review the concept of infection prevention by probiotics and the present knowledge of the efficacy of probiotics in prevention of infections among patients with abdominal diseases and in intensive care. Safety issues of probiotics will be discussed extensively.

RECENT FINDINGS

Over 30 clinical trials with probiotics to prevent infections have been published, some of which were prematurely stopped recently. Studies with critically ill patients and patients with abdominal diseases showed conflicting results regarding the effects of probiotics on infection rates, as did meta-analyses. These studies are difficult to compare because different probiotics were used which all have different efficacy and safety profiles.

SUMMARY

The efficacy of probiotics in infection prevention among critically ill patients is still not unequivocally determined. The safety profile differs per probiotic strain and should not be generalized towards other strains and patient populations. A well designed and well powered clinical trial with clear endpoints to demonstrate efficacy is warranted.

Critical illness, gastrointestinal complications, and medication therapy during enteral feeding in critically ill adult patients

Critically ill patients who are subjected to high stress or with severe injury can rapidly break down their body protein and energy stores. Unless adequate nutrition is provided, malnutrition and protein wasting may occur, which can negatively affect patient outcome. Enteral nutrition (EN) is the mainstay of nutrition support therapy in patients with a functional gastrointestinal (GI) tract who cannot take adequate oral nutrition. EN in critically ill patients provides the benefits of maintaining gut functionality, integrity, and immunity as well as decreasing infectious complications. However, the ability to provide timely and adequate EN to critically ill patients is often hindered by GI motility disorders and complications associated with EN. This paper reviews the GI complications and intolerances associated with EN in critically ill patients and provides recommendations for their prevention and treatment. It also addresses the role of commonly used medications in the intensive care unit and their impact on GI motility and EN delivery.

Systematic review and meta-analysis of enteral nutrition formulations in acute pancreatitis

BACKGROUND

Although the benefits of enteral nutrition in acute pancreatitis are well established, the optimal composition of enteral feeding is largely unknown. The aim of the study was to compare the tolerance and safety of enteral nutrition formulations in patients with acute pancreatitis.

METHODS

Electronic databases (Scopus, MEDLINE, Cochrane Controlled Clinical Trials Register) and the proceedings of major pancreatology conferences were searched.

RESULTS

Twenty randomized controlled trials, including 1070 patients, met the inclusion criteria. None of the following was associated with a significant difference in feeding intolerance: the use of (semi)elemental versus polymeric formulation (relative risk (RR) 0.62 (95 per cent confidence interval (c.i.) 0.10 to 3.97); P = 0.611); supplementation of enteral nutrition with probiotics (RR 0.69 (95 per cent c.i. 0.43 to 1.09); P = 0.110); or immunonutrition (RR 1.60 (95 per cent c.i. 0.31 to 8.29); P = 0.583). The risk of infectious complications and death did not differ significantly in any of the comparisons.

CONCLUSION

The use of polymeric, compared with (semi)elemental, formulation does not lead to a significantly higher risk of feeding intolerance, infectious complications or death in patients with acute pancreatitis. Neither the supplementation of enteral nutrition with probiotics nor the use of immunonutrition significantly improves the clinical outcomes.