Associations of Dietary Intake with the Intestinal Microbiota and Short-Chain Fatty Acids Among Young Adults with Type 1 Diabetes and Overweight or Obesity.

BACKGROUND: Diet, a key component of type 1 diabetes (T1D) management, modulates the intestinal microbiota and its metabolically active byproducts-including SCFA-through fermentation of dietary carbohydrates such as fiber. However, the diet-microbiome relationship remains largely unexplored in longstanding T1D. OBJECTIVES: We evaluated whether increased carbohydrate intake, including fiber, is associated with increased SCFA-producing gut microbes, SCFA, and intestinal microbial diversity among young adults with longstanding T1D and overweight or obesity. METHODS: Young adult men and women with T1D for ≥1 y, aged 19-30 y, and BMI of 27.0-39.9 kg/m2 at baseline provided stool samples at baseline and 3, 6, and 9 mo of a randomized dietary weight loss trial. Diet was assessed by 1-2 24-h recalls. The abundance of SCFA-producing microbes was measured using 16S rRNA gene sequencing. GC-MS measured fecal SCFA (acetate, butyrate, propionate, and total) concentrations. Adjusted and Bonferroni-corrected generalized estimating equations modeled associations of dietary fiber (total, soluble, and pectins) and carbohydrate (available carbohydrate, and fructose) with microbiome-related outcomes. Primary analyses were restricted to data collected before COVID-19 interruptions. RESULTS: Fiber (total and soluble) and carbohydrates (available and fructose) were positively associated with total SCFA and acetate concentrations (n = 40 participants, 52 visits). Each 10 g/d of total and soluble fiber intake was associated with an additional 8.8 µmol/g (95% CI: 4.5, 12.8 µmol/g; P = 0.006) and 24.0 µmol/g (95% CI: 12.9, 35.1 µmol/g; P = 0.003) of fecal acetate, respectively. Available carbohydrate intake was positively associated with SCFA producers Roseburia and Ruminococcus gnavus. All diet variables except pectin were inversely associated with normalized abundance of Bacteroides and Alistipes. Fructose was inversely associated with Akkermansia abundance. CONCLUSIONS: In young adults with longstanding T1D, fiber and carbohydrate intake were associated positively with fecal SCFA but had variable associations with SCFA-producing gut microbes. Controlled feeding studies should determine whether gut microbes and SCFA can be directly manipulated in T1D.

Possible role of gut microbes and host's immune response in gut-lung homeostasis.

The vast diversity of microbial communities reside in various locations of the human body, and they are collectively named as the 'Human Microbiota.' The majority of those microbes are found in the gastrointestinal and respiratory tracts. The microorganisms present in the gastrointestinal and the respiratory tracts are called the gut microbiota and the airway microbiota, respectively. These microbial communities are known to affect both the metabolic functions and the immune responses of the host. Among multiple factors determining the composition of gut microbiota, diet has played a pivotal role. The gut microbes possess enzymatic machinery for assimilating dietary fibers and releasing different metabolites, primarily short-chain fatty acids (SCFAs). The SCFAs modulate the immune responses of not only the gut but other distal mucosal sites as well, such as the lungs. Dysbiosis in normal gut flora is one of the factors involved in the development of asthma and other respiratory disorders. Of note, several human and murine studies have indicated significant cross-talk between gut microbiota and lung immunity, known as the gut-lung axis. Here, in this review, we summarize the recent state of the field concerning the effect of dietary metabolites, particularly SCFAs, on the "gut-lung axis" as well as discuss its impact on lung health. Moreover, we have highlighted the role of the "gut-lung axis" in SARS-CoV-2 mediated inflammation. Also, to analyze the global research progress on the gut-lung axis and to identify the knowledge gap in this field, we have also utilized the bibliographic tools Dimension database and VOS viewer analysis software. Through network mapping and visualization analysis, we can predict the present research trend and the possibility to explore new directions.

Editorial of the Special Issue "Dietary Fiber and Inflammatory Bowel Disease".

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic disease of the gastrointestinal (GI) tract; its burden has significantly increased in recent decades, with 6.8 million cases of IBD reported in 2017 according to the Global Burden of Disease study [...].

Online information in Spanish on probiotics, yoghurt, kefir, kombucha, fibre and prebiotics: an analysis of the quality of information and the certainty of the evidence supporting health claims.

OBJECTIVE: To examine the certainty of the evidence supporting health claims about probiotics, yoghurt, kefir, kombucha, fibre and prebiotics, and to assess the quality of online information in Spanish. DESIGN: Content analysis. METHODS: We compiled a data set of 114 web pages by searching six popular search phrases in Spanish relating to probiotics, yoghurt, kefir, kombucha, fibre and prebiotics on Google.es and coded them for typology and health claims. We examined the certainty of the evidence for health claims from systematic reviews. Information quality was assessed according to 10 criteria, where a web page: mentions scientific publications and reports their conclusions; quantifies relative and absolute effects; acknowledges some limitations; discusses certainty of evidence; reports the potential harms, alternatives and costs; and does not argue based on personal experiences. RESULTS: Gastrointestinal health (86.0%), general health (57.9%), cardiovascular health (53.5%) and immune system health (50.9%) were the most widely mentioned topics. Half of claims (52.6%, 70/133) were supported by evidence from systematic reviews. Probiotics had the highest number of claims supported by evidence and kombucha the lowest. The highest certainty was found for antibiotic-associated diarrhoea, necrotising enterocolitis and otitis (moderate) in probiotics and yoghurt, infectious diarrhoea and hepatic encephalopathy (moderate) in prebiotics, and cardiovascular health (high to moderate) and colorectal cancer (moderate) in fibre. On a scale of 0-10, the median information quality score for all web pages was 3. Only 18.4% reported study conclusions, 7.9% quantified the effects, 28.9% acknowledged some limitations in the research and 42.1% reported potential harms. CONCLUSIONS: Most online health claims for dietary interventions intended for improving health through the gut microbiome are supported by low or very low certainty of evidence. Online information does not align with the evidence and is incomplete or unbalanced.

Analysis of the Nutritional Value of the Diets Presented in Women's and Sports Magazines before and during the COVID-19 Pandemic.

For consumers, among the most important sources of information related to nutrition are popular journals and magazines, including women's and sports, but the diets presented there may lead to unhealthy weight-control behaviors. The aim of the study was to assess the nutritional value of regular and low-calorie diets presented in Polish women's and sports magazines before and during COVID-19 pandemic. The study was based on two popular Polish magazines-one women's magazine and one sports magazine, which regularly present various types of diets. The nutritional value of all the diets published from January 2014 to May 2022 was analyzed. The total number of included single-day menus was n = 119, while for analysis they were stratified based on: type of magazine (published in the women's magazine n = 41 and in the sports magazine n = 78), year of publication (before the COVID-19 pandemic n = 78 and during n = 41), and type of diet (regular n = 61 and low-calorie n = 58). The analysis included the energy value and nutritional value. For the type of magazine, the diets published in the sports magazine were characterized by a higher intake of fat (p < 0.0001 for intake in grams and in % of energy) and calcium (p = 0.0330), whereas the diets published in the women's magazine were characterized by a higher intake of carbohydrates (p = 0.0226 for intake in grams, and p = 0.0002 for intake in % of energy) and fiber (p = 0.0163). For the year of publication, the diets published during the COVID-19 pandemic were characterized by a higher intake of protein (p = 0.0166 for intake in grams), sodium (p = 0.0465), calcium (p < 0.0001), vitamin D (p = 0.0197), vitamin B6 (p = 0.0207), and vitamin B12 (p = 0.0277), whereas the diets published before the COVID-19 pandemic were characterized by a higher intake of carbohydrates (p = 0.0243 for intake in % of energy). For the type of diet, the regular diets were characterized by a higher energy value (p = 0.0020), as well as by a higher intake of fat (p = 0.0162 for intake in grams), carbohydrates (p = 0.0390 for intake in grams), mono- and oligosaccharides (p = 0.0084 for intake in % of energy), fiber (p < 0.0001), magnesium (p = 0.0323), iron (p = 0.0307), and vitamin B6 (p = 0.0204). The nutritional value of the diets presented in the Polish women's and sports magazines was not justified by the type of magazine or type of diet, associated with the target group, which may cause the following of improperly balanced diets. However, the changes in the typical nutritional value of diets presented in the Polish women's and sports magazines during the COVID-19 pandemic were justified by some specific needs for the prevention and treatment of COVID-19.

A high-fibre personalised dietary advice given via a web tool reduces constipation complaints in adults.

Constipation can greatly impact the quality of life (QoL), which can be relieved by dietary fibres; however, preserving a higher fibre intake remains a challenge. We investigated the effects of a personalised dietary advice (PDA) on fibre intake and mild constipation complaints. A total number of twenty-five adults with mild constipation complaints were included in a 4-week observation period followed by a 4-week personalised intervention. The PDA provided high-fibre alternatives via a web tool. In weeks 1, 4 and 8, dietary intake, constipation complaints and QoL were assessed. Furthermore, participants collected a faecal sample at weeks 1, 4 and 8 to determine microbiota diversity and composition, and short-chain fatty acids (SCFA). Participants completed questions daily for 8 weeks regarding abdominal complaints, stool frequency and stool consistency. Fibre intake in week 8 was significantly higher compared to week 1 (Δ = 5·7 ± 6·7 g, P < 0·001) and week 4 (Δ = 5·2 ± 6·4 g, P < 0·001). Constipation severity and QoL significantly improved at week 8 compared to the observation period (P < 0·001). A higher fibre intake significantly reduced constipation severity (ß = -0·031 (-0·05; -0·01), P = 0·001) and the QoL (ß = -0·022 (-0·04; -0·01), P = 0·009). Stool consistency (P = 0·040) and abdominal pain (P = 0·030) improved significantly during the intervention period (P = 0·040), but stool frequency did not. Average microbial alpha diversity and composition and SCFA concentrations did not change over time, but indicated individual-specific dynamics. Several SCFAs were associated with constipation complaints. To conclude, a PDA effectively increased fibre intake and subsequently reduced constipation complaints, indicating that guided dietary adjustments are important and feasible in the treatment of mild constipation complaints.

[Correction of intestinal microbial composition disturbances as a potential link in complex therapy of patients with COVID-19].

The article reflects the potential for correcting intestinal microbiota disorders in the complex therapy of patients with COVID-19. It has been noted that the inclusion of dietary fiber in the diet contributes to protection against disruption of the integrity of the intestinal barrier and may limit bacterial translocation into the systemic circulation. The possibility of using psyllium (Mucofalk) is reflected, the action of which is realized both through its sorption, cytoprotective and anti-inflammatory properties in viral lesions of the gastrointestinal tract, and through stimulation of the own beneficial intestinal microbiota. The paper presents studies of the prospects for the use of probiotics, synbiotics in the complex therapy of patients with COVID-19. Detailed data are provided on the mechanisms of the positive effect of short-chain fatty acid preparations on reducing the severity of the disease in patients with COVID-19. It was noted that taking the drug Zacofalk leads to a significant increase in its own butyrate-producing microbiota (Faecalibacterium prausnitzii) and suppression of the growth of opportunistic flora with pro-inflammatory activity. The results of a recent study are presented showing that in patients with a mild course of COVID infection with respiratory and intestinal symptoms, the administration of Zakofalk for 30 days (3 tablets per day) led to significantly faster stool normalization (by day 7), persistent normalization of the frequency and consistency of stools by the 21st day and a significantly more pronounced regression of bloating and abdominal pain, as well as a decrease in the risk of developing post-infectious irritable bowel syndrome.

RNA-Seq Reveals Differentially Expressed Genes Associated with High Fiber Quality in Abaca (Musa textilis Nee).

Despite the importance of and current demand for abaca (Musa textilis Nee) fiber, there has been limited study that capitalizes on RNA-seq to identify candidate genes associated with high fiber quality and bunchy top virus (AbBTV) resistance. Three varieties (Abuab, Inosa, and Tangongon), one wild banana variety (Musa balbisiana Colla) Pacol, and two developed backcrosses (Abuab × Pacol BC2 and BC3) were grown at the Institute of Plant Breeding (IPB), Laguna, Philippines. The pseudostems of 3-month-old suckers of each genotype were sampled for RNA-seq. Datasets were analyzed for differential expression (DE) implementing various model frameworks, including pairwise, genotypic and non-DE models. Results indicate that Abuab and BC3 induce the highest proportion (70%) of abaca-specific genes. Gene ontology (GO) enrichment analysis showed several genes associated with cellulose synthase activity, callose synthase, ß-glucosidase activity, glucan biosynthetic process, etc. KEGG pathway analysis showed several genes encoding for enzymes involved in the lignin biosynthetic pathway. Analysis using genotypic DE (GDE) between abaca bunchy top virus (AbBTV)-resistant and -susceptible groups revealed genes such as pathogenesis-related protein and NBS-LRR. As the genotypes were not infected with the pathogen, these genes are yet to be confirmed for their roles in disease resistance and are an interesting subject for further investigation.

Potential Association Between Dietary Fibre and Humoral Response to the Seasonal Influenza Vaccine.

Influenza vaccination is an effective public health measure to reduce the risk of influenza illness, particularly when the vaccine is well matched to circulating strains. Notwithstanding, the efficacy of influenza vaccination varies greatly among vaccinees due to largely unknown immunological determinants, thereby dampening population-wide protection. Here, we report that dietary fibre may play a significant role in humoral vaccine responses. We found dietary fibre intake and the abundance of fibre-fermenting intestinal bacteria to be positively correlated with humoral influenza vaccine-specific immune responses in human vaccinees, albeit without reaching statistical significance. Importantly, this correlation was largely driven by first-time vaccinees; prior influenza vaccination negatively correlated with vaccine immunogenicity. In support of these observations, dietary fibre consumption significantly enhanced humoral influenza vaccine responses in mice, where the effect was mechanistically linked to short-chain fatty acids, the bacterial fermentation product of dietary fibre. Overall, these findings may bear significant importance for emerging infectious agents, such as COVID-19, and associated de novo vaccinations.

Dietary fibre to reduce colon cancer risk in Alaska Native people: the Alaska FIRST randomised clinical trial protocol.

INTRODUCTION: Diet, shown to impact colorectal cancer (CRC) risk, is a modifiable environmental factor. Fibre foods fermented by gut microbiota produce metabolites that not only provide food for the colonic epithelium but also exert regulatory effects on colonic mucosal inflammation and proliferation. We describe methods used in a double-blinded, randomised, controlled trial with Alaska Native (AN) people to determine if dietary fibre supplementation can substantially reduce CRC risk among people with the highest reported CRC incidence worldwide. METHODS AND ANALYSES: Eligible patients undergoing routine screening colonoscopy consent to baseline assessments and specimen/data collection (blood, urine, stool, saliva, breath and colon mucosal biopsies) at the time of colonoscopy. Following an 8-week stabilisation period to re-establish normal gut microbiota post colonoscopy, study personnel randomise participants to either a high fibre supplement (resistant starch, n=30) or placebo (digestible starch, n=30) condition, repeating stool sample collection. During the 28-day supplement trial, each participant consumes their usual diet plus their supplement under direct observation. On day 29, participants undergo a flexible sigmoidoscopy to obtain mucosal biopsy samples to measure the effect of the supplement on inflammatory and proliferative biomarkers of cancer risk, with follow-up assessments and data/specimen collection similar to baseline. Secondary outcome measures include the impact of a high fibre supplement on the oral and colonic microbiome and biofluid metabolome. ETHICS AND DISSEMINATION: Approvals were obtained from the Alaska Area and University of Pittsburgh Institutional Review Boards and Alaska Native Tribal Health Consortium and Southcentral Foundation research review bodies. A data safety monitoring board, material transfer agreements and weekly study team meetings provide regular oversight throughout the study. Study findings will first be shared with AN tribal leaders, health administrators, providers and community members. Peer-reviewed journal articles and conference presentations will be forthcoming once approved by tribal review bodies. TRIAL REGISTRATION NUMBER: NCT03028831.

The lung-gut axis during viral respiratory infections: the impact of gut dysbiosis on secondary disease outcomes.

Bacteria that colonize the human gastrointestinal tract are essential for good health. The gut microbiota has a critical role in pulmonary immunity and host's defense against viral respiratory infections. The gut microbiota's composition and function can be profoundly affected in many disease settings, including acute infections, and these changes can aggravate the severity of the disease. Here, we discuss mechanisms by which the gut microbiota arms the lung to control viral respiratory infections. We summarize the impact of viral respiratory infections on the gut microbiota and discuss the potential mechanisms leading to alterations of gut microbiota's composition and functions. We also discuss the effects of gut microbial imbalance on disease outcomes, including gastrointestinal disorders and secondary bacterial infections. Lastly, we discuss the potential role of the lung-gut axis in coronavirus disease 2019.

Could the Induction of Trained Immunity by ß-Glucan Serve as a Defense Against COVID-19?

As the SARS-CoV-2 virus wreaks havoc on the populations, health care infrastructures and economies of nations around the world, finding ways to protect health care workers and bolster immune responses in the general population while we await an effective vaccine will be the difference between life and death for many people. Recent studies show that innate immune populations may possess a form of memory, termed Trained Immunity (TRIM), where innate immune cells undergo metabolic, mitochondrial, and epigenetic reprogramming following exposure to an initial stimulus that results in a memory phenotype of enhanced immune responses when exposed to a secondary, heterologous, stimulus. Throughout the literature, it has been shown that the induction of TRIM using such inducers as the BCG vaccine and ß-glucan can provide protection through altered immune responses against a range of viral infections. Here we hypothesize a potential role for ß-glucan in decreasing worldwide morbidity and mortality due to COVID-19, and posit several ideas as to how TRIM may actually shape the observed epidemiological phenomena related to COVID-19. We also evaluate the potential effects of ß-glucan in relation to the immune dysregulation and cytokine storm observed in COVID-19. Ultimately, we hypothesize that the use of oral ß-glucan in a prophylactic setting could be an effective way to boost immune responses and abrogate symptoms in COVID-19, though clinical trials are necessary to confirm the efficacy of this treatment and to further examine differential effects of ß-glucan's from various sources.

Analysis of the intricate effects of polyunsaturated fatty acids and polyphenols on inflammatory pathways in health and disease.

Prevention and treatment of non-communicable diseases (NCDs), including cardiovascular disease, diabetes, obesity, cancer, Alzheimer's and Parkinson's disease, arthritis, non-alcoholic fatty liver disease and various infectious diseases; lately most notably COVID-19 have been in the front line of research worldwide. Although targeting different organs, these pathologies have common biochemical impairments - redox disparity and, prominently, dysregulation of the inflammatory pathways. Research data have shown that diet components like polyphenols, poly-unsaturated fatty acids (PUFAs), fibres as well as lifestyle (fasting, physical exercise) are important factors influencing signalling pathways with a significant potential to improve metabolic homeostasis and immune cells' functions. In the present manuscript we have reviewed scientific data from recent publications regarding the beneficial cellular and molecular effects induced by dietary plant products, mainly polyphenolic compounds and PUFAs, and summarize the clinical outcomes expected from these types of interventions, in a search for effective long-term approaches to improve the immune system response.

Targeting the gut-lung microbiota axis by means of a high-fibre diet and probiotics may have anti-inflammatory effects in COVID-19 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1 is a 2019 novel coronavirus, which only in the European area has led to more than 300,000 cases with at least 21,000 deaths. This manuscript aims to speculate that the manipulation of the microbial patterns through the use of probiotics and dietary fibers consumption may contribute to reduce inflammation and strengthen the immune system response in COVID-19 infection. The reviews of this paper are available via the supplemental material section.