Prior research has explored the effect of synbiotics, the combination of probiotics and prebiotics, on the gut microbiota in clinical populations. However, evidence related to the effect of synbiotics on the gut microbiota in healthy adults has not been reviewed to date. A systematic review and meta-analysis was conducted to comprehensively investigate the effect of synbiotics on the gut microbiota and inflammatory markers in populations of healthy adults. Scopus, PubMed, Web of Science, ScienceDirect, MEDLINE, CINAHL, and The Cochrane Library were systematically searched to retrieve randomized controlled trials examining the primary outcome of gut microbiota or intestinal permeability changes after synbiotic consumption in healthy adults. Secondary outcomes of interest were short-chain fatty acids, inflammatory biomarkers, and gut microbiota diversity. Weighted (WMD) or standardized mean difference (SMD) outcome data were pooled in restricted maximum likelihood models using random effects. Twenty-seven articles reporting on 26 studies met the eligibility criteria (n = 1319). Meta-analyses of 16 studies showed synbiotics resulted in a significant increase in Lactobacillus cell count (SMD, 0.74; 95% confidence interval [CI], 0.15, 1.33; P = 0.01) and propionate concentration (SMD, 0.22; 95% CI, 0.02, 0.43; P = 0.03) compared with controls. A trend for an increase in Bifidobacterium relative abundance (WMD, 0.97; 95% CI, 0.42, 2.52; P = 0.10) and cell count (SMD, 0.82; 95% CI, 0.13, 1.88; P = 0.06) was seen. No significant differences in α-diversity, acetate, butyrate, zonulin, IL-6, CRP, or endotoxins were observed. This review demonstrates that synbiotics modulate the gut microbiota by increasing Lactobacillus and propionate across various healthy adult populations, and may result in increased Bifidobacterium. Significant variations in synbiotic type, dose, and duration should be considered as limitations when applying findings to clinical practice. PROSPERO no. CRD42021284033.

Ulcerative Colitis (UC), a type of Inflammatory Bowel Disease (IBD), is a chronic, relapsing gastrointestinal condition with increasing global prevalence. The gut microbiome profile of people living with UC differs from healthy controls and this may play a role in the pathogenesis and clinical management of UC. Probiotics have been shown to induce remission in UC; however, their impact on the gut microbiome and inflammation is less clear. Anthocyanins, a flavonoid subclass, have shown anti-inflammatory and microbiota-modulating properties; however, this evidence is largely preclinical. To explore the combined effect and clinical significance of anthocyanins and a multi-strain probiotic, a 3-month randomised controlled trial will be conducted in 100 adults with UC. Participants will be randomly assigned to one of four groups: anthocyanins (blackcurrant powder) + placebo probiotic, probiotic + placebo fruit powder, anthocyanin + probiotic, or double placebo. The primary outcome is a clinically significant change in the health-related quality-of-life measured with the Inflammatory Bowel Disease Questionnaire-32. Secondary outcomes include shotgun metagenomic sequencing of the faecal microbiota, faecal calprotectin, symptom severity, and mood and cognitive tests. This research will identify the role of adjuvant anti-inflammatory dietary treatments in adults with UC and elucidate the relationship between the gut microbiome and inflammatory biomarkers in this disease, to help identify targeted individualised microbial therapies. ANZCTR registration ACTRN12623000630617.

Background: Few studies have explored the relationship between habitual dietary patterns and disease activity in people with Inflammatory Bowel Disease (IBD). This cross-sectional study explored the association between dietary patterns and clinical and objective markers of inflammation in adults from the Australian IBD Microbiome Study. Methods: Dietary patterns were derived using principal component analysis (PCA) of baseline food frequency questionnaire data. Food intake was quantified using 3-day food record data. Associations between dietary intake and both clinical disease activity index (CDAI) and faecal calprotectin (FCP) were analysed. Results: Participants included 412 adults (IBD = 223, Healthy controls (HC) = 189). Both cohorts consumed poor-quality diets with inadequate servings of most food groups compared to Australian reference standards. IBD participants without FCP inflammation had significantly higher fibre intake than those with moderate FCP. In the Crohn’s Disease group, high adherence to ‘High plant diversity’ and ‘Meat eaters’ dietary patterns were associated with increased CDAI and FCP, respectively. In the combined IBD cohort, high adherence to a ‘Vegan-style’ dietary pattern was associated with increased FCP. Conclusions: There is a need for dietary modifications among Australian adults, both with and without IBD, to improve dietary fibre intake and adherence to dietary guidelines. Dietary patterns characterised by a high intake of plant foods or meat products were both positively associated with indicators of active IBD. It is possible that some participants with active IBD were modifying their diet to try to manage their disease and reduce symptoms, contributing to the association between healthier dietary patterns and active disease. Further clinical and longitudinal studies are needed to expand upon the findings. This study offers a unique contribution by utilising FCP as an objective marker of intestinal inflammation and applying dietary pattern analysis to investigate the relationship between diet and inflammatory markers.

Background: Inadequate health literacy in people with chronic kidney disease is associated with poorer disease management and greater complications. Adherence to the renal diet is known to be suboptimal and patient feedback about the renal diet suggests that patients leave nephrology clinics feeling confused. The present study aimed to evaluate the impact of a health literacy sensitive model of care (MOC) in outpatient nephrology dietetic clinics.Methods: This quasi‐experimental non‐randomised pre‐post study recruited adults attending three renal dietitian clinics. The revised MOC consisted of a renal diet question prompt sheet, teachback, and plain language materials and instructions. Outcomes assessed included clinical, dietary, patient‐reported satisfaction and quality of life. Differences between and within groups were analysed using paired t‐tests, independent sample t‐tests (or non‐parametric equivalent), chi‐squared and McNemar's tests. Linear mixed models evaluated change in total diet quality score, fruit, vegetable, protein and dairy intake with time as a fixed effect and a random subject specific effect.Results: Fail to attend rates at the initial appointments were lower in the revised MOC (21.5% vs. 9.1%). The revised MOC was associated with significantly improved fruit (p = 0.03) and vegetable (p = 0.003) intake and an improved proportion with adequate diet quality (p = 0.03). These impacts were of moderate effect size (d = 0.5, 95% confidence interval = 0.0–1.0). The revised MOC was also associated with greater satisfaction at baseline (p = 0.04) and higher acceptability scores for all questions at the review appointments. Quality of life improved clinically but not significantly in the revised MOC (p = 0.92).Conclusions: This low‐cost health literacy sensitive intervention is a promising strategy to improve fruit and vegetable intake in adults attending renal dietitian clinics. Further research to determine fidelity of teachback use and cost utility analysis would be beneficial. Larger scale trials powered to detect changes in quality of life would also be informative.

Background/Objectives: This study investigated the relationship between time spent on social media and eating behaviours among young Australian adults. It also examined the types of content discussed and linguistic styles used by health and nutrition content creators on Instagram. Methods: Young adults (aged 18–30 years) who reported viewing social media for nutrition or health content were recruited to complete a self-administered, cross-sectional survey. Data on demographics, time spent on Instagram and TikTok, health content creators viewed, and responses to the Scale of Effects of Social Media on Eating Behaviours (SESMEB) were collected. Associations between time spent on Instagram and TikTok and SESMEB scores were analysed. Inductive content and thematic analysis were conducted on health-related posts from Instagram accounts viewed by study participants. Results: From the 57 participants who completed the demographic survey, 42 participants completed the full study including the SESMEB survey. There was no significant association between SESMEB score and time spent on Instagram (p = 0.38) or TikTok (p = 0.40). A total of 1420 Instagram posts from 71 distinct content creators were analysed. Health and fitness product endorsements or advertisements (56.3%), predominantly posted by laypersons (55.3%), were the most common type of post in the sample. The most common communication style was ‘expert advice’ (47.9%), with ‘informal language’ (85.9%) as the dominant linguistic style. Results from thematic analysis suggest health and nutrition information on social media is often presented to consumers in emotionally charged, stylised, or contradictory ways and requires users to sift through conflicting messages, aesthetics, and ideologies to construct their own understanding of health. Conclusions: This study suggests that young adults are primarily exposed to health and fitness product promotions from unqualified content creators on social media. Dietitians and nutrition professionals may need to consider adopting specific linguistic and communication styles to enhance the dissemination and engagement of credible nutrition information online. These findings have implications for improving digital health literacy and strengthening the impact of evidence-based nutrition messaging in digital environments.