Fermented foods and inflammation: A systematic review and meta-analysis of randomized controlled trials

Diet, Food, and Nutritional Exposures and Inflammatory Bowel Disease or Progression of Disease: an Umbrella Review

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), contributes to substantial morbidity. Understanding the intricate interplay between dietary factors and the incidence and progression of IBD is essential for developing effective preventative and therapeutic strategies. This umbrella review comprehensively synthesizes evidence from systematic reviews and meta-analyses to evaluate these complex associations. Dietary factors associated with an increased incidence and/or progression of IBD include a high intake of red and processed meat, other processed foods, and refined sugars, together with a low intake of vegetables, fruits, and fiber. For most other food groups, the results are mixed or indicate no clear associations with IBD, CD, and UC. Some differences seem to exist between UC and CD and their risk factors, with increased intake of dietary fiber being inversely associated with CD incidence but not clearly associated with UC. Dietary fiber may contribute to maintaining the gut epithelial barrier and reduce inflammation, often through interactions with the gut microbiota. This seems to play an important role in inflammatory mechanisms in the gut and in IBD incidence and progression. Diets low in fermentable saccharides and polyols can alleviate symptom burden, but there are concerns regarding their impact on the gut microbiota and their nutritional adequacy. Mediterranean diets, vegetarian diets, and a diet low in grains, sugars, and lactose (specific carbohydrate diet) are also associated with lower incidence and/or progression of IBD. The associations of dietary patterns are mirrored by inflammatory biomarkers. IBD is typically treated pharmaceutically; however, many patients have a suboptimal response to medical treatments. The findings from this umbrella review could provide evidence for nutritional counseling and be a valuable addition to traditional treatment plans for IBD. This systematic review was registered at PROSPERO as CRD440252.

Anti-inflammatory effects of a naturally lacto-fermented cucumber product on RAW 264.7 macrophages in association with increased functional ingredients

A naturally lacto-fermented cucumber product was developed for use as anti-inflammatory functional foods. To explore the anti-inflammatory characteristics, water (CWE) and ethanol extracts (CEE) from this product were selected to assess their anti-inflammatory potential on RAW 264.7 macrophages in the absence or presence of lipopolysaccharide (LPS), using four different inflammatory models. Changes in pro- (IL-1β, IL-6 and TNF-α) and anti-inflammatory (IL-10) cytokine secretions by treated macrophages were measured using ELISA. The results showed that both CWE and CEE had strong potential to inhibit LPS-stimulated inflammation in macrophages in a repair manner. CWE had a better effect than CEE. The total phenolic, flavonoid and saponin contents in CEE were significantly (P < 0.05) correlated with IL-10 (r = 0.384, P = 0.036*) and TNF-α (r = 0.371, P = 0.043*) levels, but slightly correlated with TNF-α/IL-10 secretion ratios (r = -0.184, P = 0.359) by treated RAW 264.7 cells, respectively.

The impact of botanical fermented foods on metabolic syndrome and type 2 diabetes: a systematic review of randomised controlled trials

Our systematic review assessed the impact of botanical fermented food (BFF) consumption on glucose, lipid, anthropometric, inflammatory and gut microbiota parameters, in adults with metabolic syndrome (MetS), MetS components or type 2 diabetes mellitus (T2DM). Embase, MEDLINE, Cochrane CENTRAL and Google Scholar were searched with no language limits, from inception to 31 August 2022, for eligible randomised controlled trials (RCTs). Two independent reviewers screened 6873 abstracts and extracted relevant data. Risk of bias (ROB) was assessed using the Cochrane Collaboration's ROB2 tool. The final review included twenty-six RCTs, with thirty-one reports published between 2001 and 2022. Significant (p < 0·05) within-group and between-group changes in cardiometabolic outcome means were reported in twenty-three and nineteen studies, respectively. Gut microbiota composition was assessed in four studies, with two finding significant between-group differences. No significant difference between groups of any measured outcomes was observed in five studies. There were fourteen studies at low ROB; ten were of some concern; and two were at high ROB. In 73% of included studies, BFF consumption by participants with obesity, MetS or T2DM led to significant between-group improvements in discrete cardiometabolic outcomes, including fasting blood glucose, lipid profile, blood pressure, waist circumference, body fat percentage and C-reactive protein. BFF consumption increased the abundance of beneficial gut bacteria, such as Bifidobacterium and LAB, whilst reducing potential pathogens such as Bacteroides. To determine the clinical significance of BFFs as therapeutic dietary adjuncts, their safety, tolerability and affordability must be balanced with the limited power and magnitude of these preliminary findings.

The inhibitory effects of plant additives on biogenic amine formation in fermented foods - a review

Fermented food has unique properties and high nutritional value, and thus, should constitute a basic element of a balanced and health-promoting diet. However, it can accumulate considerable amount of biogenic amines (BAs), which ingested in excess can lead to adverse health effects. The application of plant-derived additives represents a promising strategy to ensure safety or enhance the functional and organoleptic properties of fermented food. This review summarizes currently available data on the application of plant-origin additives with the aim to reduce BA content in fermented products. The importance of ensuring fermented food safety has been highlighted considering the growing evidence of beneficial effects resulting from the consumption of this type of food, as well as the increasing number of individuals sensitive to BAs. The examined plant-origin additives reduced the BA concentration to varying degrees, and their efficacy depended on the type of additive, matrix, autochthonous, and inoculated microorganisms, as well as the manufacturing conditions. The main mechanisms of action include antimicrobial effects and the inhibition of microbial decarboxylases. Further research on the optimization of bioactive substances extraction, standardization of their chemical composition, and development of detailed procedures for its use in fermented products manufacturing are needed.

Mapping the available evidence on the impact of ingested live microbes on health: a scoping review protocol

INTRODUCTION

It has been hypothesised that the regular consumption of safe, live microbes confers health-promoting attributes, including the prevention of disease. To address this hypothesis, we propose a scoping review approach that will systematically assess the large corpus of relevant literature that is now available on this research topic. This article outlines a protocol for a scoping review of published studies on interventions with live microbes in non-patient populations across eight health categories. The scoping review aims to catalogue types of interventions, measured outcomes, dosages, effectiveness, as well as current research gaps.

METHODS AND ANALYSIS

The scoping review will follow the six-staged protocol as proposed by Arksey and O'Malley and will include the following stages: defining the research questions (stage 1); defining the eligibility criteria and finalising search strategy (stage 2); selection of studies based on the eligibility criteria (stage 3); development of a data extraction framework and charting of data (stage 4); aggregation of results and summarisation of findings (stage 5); and the optional consultation with stakeholders (stage 6), which will not be performed.

ETHICS AND DISSEMINATION

Since the scoping review synthesises information from existing literature, no separate ethical approval is required. The findings of the scoping review will be communicated for publication to an open-access, peer-reviewed scientific journal, presented at relevant conferences, and disseminated at future workshops with all relevant data and documents being available online through the Open Science Framework (https://osf.io/kvhe7).

Fermented maize slurry (Ogi) and its supernatant (Omidun) mitigate elevated intraocular pressure by modulating BDNF expression and glial plasticity in the retina-gut axis of glaucomatous rats

OBJECTIVES

Growing interest has been reported on the health benefits of fermented foods, which includes cognition enhancement and inflammation attenuation. BDNF is a known protectant against retinal degeneration, however, therapies that target this neurotrophic factor has been limited. Therefore, we assessed the reaction of BDNF and glial cells in glaucomatous rats and their response to treatment with fermented maize products.

METHODS

Thirty male adult rats were either injected via the episcleral vein with hypertonic saline to elevate intraocular pressure (IOP) or treated with fermented maize slurry (Ogi) or its supernatant (Omidun). Following sacrifice, the retina and duodenum were studied by immunohistochemical analysis using antibodies directed against GFAP, AIF-1 and BDNF.

RESULTS

Hypertonic saline injection produced hypertrophy of the Müller cells and increased GFAP and AIF-1 expression in the retina and gut when compared to the control. Treatment with Ogi and Omidun produced varying degrees of reduction of gliosis, protection against hypertonic saline-induced retinal ganglion cell loss, and reduced intraocular pressure. BDNF expression was downregulated following the hypertonic saline assault, while Omidun and Ogi treatment abrogated its reduction following the hypertonic saline assault.

CONCLUSIONS

Collectively, our findings suggest that acute elevation of IOP alters crosstalk between gut and retina with consequent aberrant activation of glial cells; and that probiotic bacteria like the lactic acid bacteria rich in fermented foods including Ogi and Omidun may offer neuroprotection to the ganglionic cells by attenuating the retinal glial reaction and improving BDNF activity.

Effect of lactic acid fermented foods on glycemic control in diabetic adults: a systemic review and meta-analysis of randomized controlled trials

Lactic acid bacteria (LAB) fermented foods are reported to have potential in managing glycemic control. This systematic review aimed to evaluate the effectiveness of LAB-fermented foods on improving glycemic control in adults with prediabetics or type 2 diabetes mellitus (T2DM). Randomized controlled trials (RCTs) on LAB fermentation-related foods were searched on PubMed, Cochrane, Excerpta Medica database (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. Sixteen RCTs were included, and the results concluded LAB-fermented food had significant effects in HbA1c (Z = 6.24, MD = -0.05, CI: -0.07 to -0.04, p ≤ 0.00001), fasting plasma glucose (Z = 2.50, MD = -0.16, CI: -0.29 to -0.04, p = 0.01) and fasting serum insulin (Z = 2.51, MD = -0.20, CI: -0.35 to -0.04, p = 0.01). There were significant effects on lipid profile, inflammatory markers, and body mass index in secondary analyses. Subgroup analysis suggests LAB-fermented consumption with a longer duration, younger age group and adults with T2DM, had a larger effect size. Clinicians could offer LAB-fermented food as dietary recommendations for prediabetic and diabetic adults. Larger trials are warranted to verify LAB-fermented food benefits on glycemic control. Systematic Review Registration: PROSPERO Registration No. CRD42022295220.

Microbiota and body weight control: Weight watchers within?

Background

Despite several decades of research, managing body weight remains an unsolved clinical problem. Health problems associated with dysregulated body weight, such as obesity and cachexia, exhibit several gut microbiota alterations. There is an increased interest in utilising the gut microbiota for body weight control, as it responds to intervention and plays an important role in energy extraction from food, as well as biotransformation of nutrients.

Scope of the review

This review provides an overview of the role of the gut microbiota in the physiological and metabolic alterations observed in two body weight dysregulation-related disorders, namely obesity and cachexia. Second, we assess the available evidence for different strategies, including caloric restriction, intermittent fasting, ketogenic diet, bariatric surgery, probiotics, prebiotics, synbiotics, high-fibre diet, and fermented foods – effects on body weight and gut microbiota composition. This approach was used to give insights into the possible link between body weight control and gut microbiota configuration.

Major conclusions

Despite extensive associations between body weight and gut microbiota composition, limited success could be achieved in the translation of microbiota-related interventions for body weight control in humans. Manipulation of the gut microbiota alone is insufficient to alter body weight and future research is needed with a combination of strategies to enhance the effects of lifestyle interventions.

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The gut microbiota is involved in the control of nutrient availability, appetite, and body weight.

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Both obesity and cachexia are associated with altered gut microbiota.

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Specific dietary and surgical approaches positively impact body weight and gut microbiota.

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Manipulation of the gut microbiota alone is insufficient to alter body weight in humans.

Probiotic Supplementation for Rheumatoid Arthritis: A Promising Adjuvant Therapy in the Gut Microbiome Era

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease that ultimately leads to joint destruction and functional disability. Although the exact etiology of RA is not fully understood, it is well established that gut microbiota (GM) plays a vital role in the pathogenesis of RA, with accumulating evidence suggesting that gut dysbiosis induces a chronic inflammatory response that may be linked to disease development. Of interest, patients with RA have significant changes in the intestinal microbiota compared to healthy controls, and several studies have suggested the use of probiotics as a possible adjuvant therapy for RA. Benefits of probiotic supplementation were reported in animal models of arthritis and human studies, but the current evidence regarding the effect of probiotic supplementation in the management of RA remains insufficient to make definite recommendations. Several different strains of Lactobacillus and Bifidobacteria, as single species or in mixed culture, have been investigated, and some have demonstrated beneficial effects on disease activity in RA human subjects. As of now, L.casei probiotic bacteria seems to be the strongest candidate for application as adjuvant therapy for RA patients. In this review, we highlight the role of GM in the development and progression of RA and summarize the current knowledge on the use of probiotics as a potential adjuvant therapy for RA. We also review the proposed mechanisms whereby probiotics regulate inflammation. Finally, the role of fermented foods is discussed as a possible alternative to probiotic supplements since they have also been reported to have health benefits.

Evaluation of nutrient profile, biochemical composition and anti-gastric ulcer potentialities of khambir, a leavened flat bread

Khambir is a leavened staple food among the native highlanders of Western Himalaya. It is prepared by sourdough fermentation of wheat flour with yeast (YAK) or buttermilk (BAK). Both types of bread were rich in carbohydrate, protein, dietary fiber, containing less fat and gluten, and enriched with lactic acid, vitamins, and minerals. The in vitro digestibility test showed a slow glucose-controlled release potential of khambir that reflected improved content of rapidly digestible starch, slowly digestible starch, resistant starch, and predicted glycemic index. The changes of crystallinity to amorphous structures of starch, content of protein and fatty acid, and accumulation of 17 major metabolites were evaluated through FTIR and GC-MS. The extracts of khambir alleviated cold-induced gastric ulcers in the animal model as it exhibited histoprotective and anti-inflammatory activities. This study demonstrated that the traditional leavened bread khambir is nutritious and can alleviate gastric lesions related to acute mountain sickness.

The impact of probiotic supplementation on metabolic health in healthy women of reproductive age: a systematic review

Products containing probiotics are targeted at healthy or at-risk individuals as a preventative measure to minimise disease risk. Most studies assessing the efficacy of probiotics in humans include a mixture of healthy and unhealthy populations, while studies that focus solely on female populations are largely limited to pregnancy or those with health conditions. Pre-conception is a significant time-point during the life-course, and improving female health status during this period may positively influence future offspring. The objective of this review is to assess the effect of probiotics administered in oral capsule formulation, on metabolic and immune markers in healthy, non-pregnant women of reproductive age. This review followed the PRISMA guidelines. Pubmed, EMBASE, CINAHL, and Web of Science were searched for relevant studies. English language articles relating to randomised-controlled trials were included. The search returned 3250 publications after duplicates were removed. Title (2516), abstract (642), and full text (87) screening excluded 3993 studies from consideration. Five papers were identified with outcomes of interest, and analysis of these showed no conclusive evidence that probiotic capsule supplementation elicited positive effects in this healthy population. This study highlights the need for further research to investigate the role that probiotics play during the pre-conception period, on female metabolic and immune health.

The effect of fortified Dadih (fermented buffalo milk) with vitamin D3 on caecum cholesterol concentration and high sensitivity c-reactive protein (hs-CRP) level in type 2 diabetes mellitus rat model

Type 2 diabetes mellitus (T2DM) may be developed by a cardiovascular complication. T2DM and its complications associated with a decrease in levels of 25 hydroxyvitamin D below normal.  The level of 25-OH-D can increase and it can be gained by probiotics supplementation. Dadih is a probiotic useful as antidiabetic, antiatherosclerotic, and it can reduce serum cholesterol. Vitamin D is beneficial for T2DM since it improves insulin production, acts as an anti-inflammatory and prevents dyslipidemia thereby preventing cardiovascular disease. This research aims to investigate the effects of giving dadih-fortified-vitamin-D3 toward caecum-cholesterol-concentration and hs-CRP-levels to T2DM-induced-rats. This study used a randomized pre-post test with control group design in 30 Wistar rats divided into 5 groups, namely T1, T2, and T3-treatment-groups. T3-group was given dadih-fortified-vitamin-D3, while T1 and T2-groups were given vitamin-D3 and dadih, respectively. The control groups were healthy-control (C1), and T2DM (C2). The intervention was given through oral sonde for 28days. The variables analyzed were caecal-cholesterol-concentrations using a spectrophotometer and hs-CRP using the ELISA method. The statistical tests were used for the caecum-cholesterol-concentration and hs-CRP levels. The mean of caecum-cholesterol-concentration in the T3-group (83.68 ±1.93mg.100g-1), was higher than T1 (77.99 ±1.70; p = 0.004) and C2-control (24.39 ±1.47; p = 0.0001). The mean of hs-CRP-level post-intervention in the T3-group (4.21 ±0.41 ng.mL-1), was lower than C2 (17.15 ±0.85;p = 0.0001), T1 (6.59 ±0.27; p = 0.0001) and T2 (5.43 ±0.39; p = 0.004). There is a very strong inverse correlation between the concentration of cholesterol and hs-CRP ( r = -0.979, p = 0.0001). The conclusion is dadih-fortified-vitamin-D3 –intervention is better than its single intervention as an anti-inflammation which might relate to the increased caecum-cholesterol-concentration.