The gut microbiome is impacted by certain types of dietary fibre. However, the type, duration and dose needed to elicit gut microbial changes and whether these changes also influence microbial metabolites remain unclear. This study investigated the effects of supplementing healthy participants with two types of non-digestible carbohydrates (resistant starch (RS) and polydextrose (PD)) on the stool microbiota and microbial metabolite concentrations in plasma, stool and urine, as secondary outcomes in the Dietary Intervention Stem Cells and Colorectal Cancer (DISC) Study. The DISC study was a double-blind, randomised controlled trial that supplemented healthy participants with RS and/or PD or placebo for 50 d in a 2 × 2 factorial design. DNA was extracted from stool samples collected pre- and post-intervention, and V4 16S rRNA gene sequencing was used to profile the gut microbiota. Metabolite concentrations were measured in stool, plasma and urine by high-performance liquid chromatography. A total of fifty-eight participants with paired samples available were included. After 50 d, no effects of RS or PD were detected on composition of the gut microbiota diversity (alpha- and beta-diversity), on genus relative abundance or on metabolite concentrations. However, Drichlet’s multinomial mixture clustering-based approach suggests that some participants changed microbial enterotype post-intervention. The gut microbiota and fecal, plasma and urinary microbial metabolites were stable in response to a 50-d fibre intervention in middle-aged adults. Larger and longer studies, including those which explore the effects of specific fibre sub-types, may be required to determine the relationships between fibre intake, the gut microbiome and host health.

Postprandially, amino acids and di/tripeptides are thought to be primarily absorbed in the proximal small intestine. However, there have been no in vivo demonstrations of regional differences in amino acid transport dynamics between the proximal and distal small intestines. We monitored plasma amino acid responses in the jejunal and ileal mesenteric veins of rats after oral administration of a diet or an amino acid mixture (Expt 1) and in the portal vein after direct administration of the amino acid mixture into the lumen of the jejunum or ileum (Expt 2). In Expt 1, the total and some amino acid concentrations in the jejunal mesenteric vein were slightly higher than those in the ileal mesenteric vein after oral administration of the amino acid mixture, suggesting that the ileum actively transports luminal amino acids to the basolateral side, comparable to the jejunum. In Expt 2, portal amino acid concentrations were elevated to a greater extent after direct administration of the amino acid mixture into the ileal lumen than into the jejunal lumen. These results demonstrate regional differences in amino acid transport dynamics in vivo and suggest that the ileum has a higher capacity for transporting amino acids than the jejunum. Our findings highlight the importance of the ileum in postprandial amino acid absorption and metabolism.

This study evaluated the effect of green tea extract and metformin and its interaction on markers of oxidative stress and inflammation in overweight women with insulin resistance. After screening, 120 women were randomly allocated in 4 groups: Placebo (PC): 1g of microcrystalline cellulose/day; Green tea (GT): 1 g (558 mg polyphenols) of standardized dry extract of green tea/day and 1 g of placebo/day; Metformin (MF): 1 g of metformin/day and 1 g of placebo/day; Green Tea and Metformin (GTMF): 1 g (558 mg polyphenols) and 1 g of metformin/day. All groups were followed-up for 12 weeks with assessment of oxidative damage to lipids and proteins, specific activity of antioxidant enzymes and inflammatory cytokine serum levels. The association of green tea with metformin significantly reduced IL-6 (GTMF: –29.7((–62.6)–20.2))(p = 0.004). Green tea and metformin isolated reduced TNF-α (GT: –12.1((–18.0)–(–3.5)); MF: –24.5((–38.60)–(–4.4)) compared to placebo (PB: 13.8 (1.2–29.2))(P < 0.001). Also, isolated metformin reduced TGF-β (MF: –25.1((–64.4)–0.04)) in comparison to placebo (PB: 6.3((–1.0)–16.3))(p = 0.038). However, when combined, their effects were nullified either for TNF-α (GTMF: 6.0((–5.7)–23.9) and for TGF-β (GTMF: –1.8((–32.1)–8.5). This study showed that there is a drug-nutrient interaction between green tea and metformin that is dependent on the cytokine analyzed.

Saccharin is a widely used sugar substitute, but little is known about the long-term health effects of saccharin intake. Our study aimed to examine the association between saccharin intake and mortality in diabetic and pre-diabetic population and overweight population from NHANES 1988–1994. Cox proportional hazard models were used to evaluate the association between saccharin intake and CVD, cancer and all-cause mortality. After multivariable adjustment, increased absolute saccharin intake was associated with the risk of all-cause mortality (hazard ratio (HR): 1·41, 95 % CI: 1·05, 1·90), CVD mortality (HR: 1·93, 95 % CI: 1·15, 3·25) and cancer mortality (HR: 2·26, 95 % CI: 1·10, 4·45) in diabetic and pre-diabetic population. Among overweight population, higher absolute saccharin intake was associated with the risk of cancer mortality (HR: 7·369, 95 % CI: 2·122, 25·592). Replacing absolute saccharin intake with total sugar significantly reduced all-cause mortality by 12·5 % and CVD mortality by 49·7 % in an equivalent substitution analysis in the diabetic and pre-diabetic population. Aspartame substitution reduced all-cause mortality by 29·2 % and cancer mortality by 30·2 %. Notably, the relative daily intake of saccharin also had similar effects as the absolute intake on all-cause, cardiovascular and cancer mortality in all analyses. This was despite the fact that the relative daily intake in our study was below the Food and Drug Administration limit of 15 mg/kg. In conclusion, our study showed a considerable risk of increased saccharin intake on the all-cause, CVD mortality and cancer mortality.

To investigate the associations between dietary patterns and biological ageing, identify the most recommended dietary pattern for ageing and explore the potential mediating role of gut microbiota in less-developed ethnic minority regions (LEMRs). This prospective cohort study included 8288 participants aged 30–79 years from the China Multi-Ethnic Cohort study. Anthropometric measurements and clinical biomarkers were utilised to construct biological age based on Klemera and Doubal’s method (KDM-BA) and KDM-BA acceleration (KDM-AA). Dietary information was obtained through the baseline FFQ. Six dietary patterns were constructed: plant-based diet index, healthful plant-based diet index, unhealthful plant-based diet index, healthy diet score, Dietary Approaches to Stop Hypertension (DASH), and alternative Mediterranean diets. Follow-up adjusted for baseline analysis assessed the associations between dietary patterns and KDM-AA. Additionally, quantile G-computation identified significant beneficial and harmful food groups. In the subsample of 764 participants, we used causal mediation model to explore the mediating role of gut microbiota in these associations. The results showed that all dietary patterns were associated with KDM-AA, with DASH exhibiting the strongest negative association (β = −0·91, 95 % CI (–1·19, −0·63)). The component analyses revealed that beneficial food groups primarily included tea and soy products, whereas harmful groups mainly comprised salt and processed vegetables. In mediation analysis, the Synergistetes and Pyramidobacter possibly mediated the negative associations between plant-based diets and KDM-AA (5·61–9·19 %). Overall, healthy dietary patterns, especially DASH, are negatively associated with biological ageing in LEMRs, indicating that Synergistetes and Pyramidobacter may be potential mediators. Developing appropriate strategies may promote healthy ageing in LEMRs.

This study aimed to identify meal and snack patterns and assess their association with sleep timing in schoolchildren. This is a cross-sectional study carried out in 2018/2019 with 1333 schoolchildren aged 7–14 years from public and private schools in Florianópolis, Brazil. Previous-day dietary intake data for breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner and evening snack were collected using a validated online questionnaire. Sleep timing was measured by the midpoint of sleep and classified as quartiles (very early, early, late and very late). Latent class analysis was performed to identify meal and snack patterns, and multinomial logistic regression was used to assess associations. Students with very late sleep timing were less likely to consume the ‘coffee with milk, bread and cheese’ breakfast pattern compared with very early group. Also, the former were more likely to consume the ‘mixed’ breakfast pattern (healthy and unhealthy foods) compared with very early students. The latter were more likely to eat the ‘Brazilian traditional, processed meat, egg and fish’ lunch pattern to the late students and less likely to consume the ‘pasta and cheese’ lunch pattern compared with the students with later sleep timing. Students with later sleep timing were more likely to eat ultra-processed food at mid-afternoon snacks compared with early group. The study findings suggest that morning preference appears to promote healthier breakfast, lunch and afternoon snack patterns, whereas later sleep timing may pose challenges in maintaining healthy patterns at these meals/snacks.

This study aimed to investigate gastrointestinal tolerability, treatment persistence and iron status markers in patients with iron deficiency anaemia (IDA) who received oral iron replacement therapy (IRT) with v. without concomitant Lactobacillus plantarum 299v (L. plantarum 299v) probiotic supplementation. A total of 295 patents with newly diagnosed IDA were randomly assigned to receive either IRT alone (n 157, IRT-only group) or IRT plus L. plantarum 299v (n 138, IRT-Pro group) in this prospective randomised non-placebo-controlled study (ClinicalTrials.gov Identifier: NCT06521879). Gastrointestinal intolerance symptoms (at baseline, within the first 30 d of IRT and at any time during 3-month IRT), serum Hb levels (at baseline and 3rd month of IRT) and iron status markers (at baseline and 3rd month of IRT) were recorded. IRT-Pro group, when compared with IRT-only group, experienced significantly lower rates of gastrointestinal intolerance over the course of IRT (13·0 % v. 46·5 %, P < 0·001) and treatment discontinuation within the first 30 d (3·6 % v. 15·9 %, P < 0·001). At 3rd month of therapy, IRT-Pro v. IRT-only group had significantly higher serum levels for iron (76·0 (51·0–96·0) v. 60·0(43·0–70·0) µg/dl, P < 0·001) and transferrin saturation (20·1 (12·5–28·5) v. 14·5 (10·5–19·0) %, P < 0·001) and higher change from baseline Hb (0·9 (0·3–1·3) v. 0·4 (–0·1–1·1) g/dl, P < 0·001) levels. Use of L. plantarum 299v probiotic supplementation during the first 30 d of IRT in IDA patients significantly reduces the gastrointestinal burden of IRT (particularly abdominal pain and bloating), the likelihood of intolerance development (by ∼3 times) and treatment discontinuation (by∼5 times), as accompanied by improved serum Hb levels and serum iron markers.

While previous studies have identified a relationship between dietary intake and the risk of non-alcoholic fatty liver disease (NAFLD), the influence of overall nutritional status on NAFLD development has not been thoroughly investigated. This study sought to explore the association between different nutritional status indicators and NAFLD among the older adults. Nutritional status was evaluated using controlling nutritional status (CONUT), prognostic nutritional index (PNI) and nutritional risk index (GNRI), while NAFLD was identified based on a controlled attenuation parameter ≥ 285 dB/m, measured using transient elastography. The analysis included multivariate regression, receiver operating characteristic analysis, eXtreme Gradient Boosting and subgroup analysis to investigate the relationships between nutritional status indices and NAFLD. The study enrolled 1409 participants for the main analysis, with an NAFLD prevalence of 44·7 %. After accounting for potential confounders, a positive association between PNI and NAFLD was observed. Participants in the third and fourth quartiles of PNI showed increased odds of NAFLD compared with the lowest quartile (Q3: OR = 1·45, 95 % CI (1·03, 2·05); Q4: OR = 2·27, 95 % CI (1·59, 3·24)). Similarly, higher GNRI quartiles were significantly associated with greater odds of NAFLD (Q4 v. Q1: aOR = 1·84; 95 % CI (1·28, 2·65)). Conversely, higher CONUT values were linked to a reduced prevalence of NAFLD (OR = 0·65, 95 % CI (0·48, 0·87)). This study highlights that suboptimal nutritional status, indicating overnutrition as evaluated by PNI, GNRI and CONUT, is positively linked with the risk of NAFLD in individuals aged 50 years and above.

The UK government launched a two-component sugar-reduction programme in 2016, one component is the taxation of sugar-sweetened beverages, the Soft Drinks Industry Levy, and the second is a voluntary sugar reduction programme for products contributing most to children’s sugar intakes. These policies provided incentives both for industry to change the products they sell and for people to change their food and beverage choices through a ‘signalling’ effect that has raised awareness of excess sugar intakes in the population. In this study, we aimed to identify the relative contributions of the supply- and demand-side drivers of changes in the sugar density of food and beverages purchased in Great Britain. While we found that both supply- and demand-side drivers contributed to decreasing the sugar density of beverage purchases (reformulation led to a 19 % reduction, product renewal 14 %, and consumer switching between products 8 %), for food products it was mostly supply-side drivers (reformulation and product renewal). Reformulation contributed consistently to a decrease in the sugar density of purchases across households, whereas changes in consumer choices were generally in the opposite direction, offsetting benefits of reformulation. We studied the social gradient of sugar density reduction for breakfast cereals, achieved mostly by reformulation, and found increased reductions in sugar purchased by households of lower socio-economic status. Conversely, there was no social gradient for soft drinks. We conclude that taxes and reformulation incentives are complementary and combining them in a programme to improve the nutritional quality of foods increases the probability of improvements in diet quality.

Tea can improve the progression of some metabolic diseases through anti-inflammatory and antioxidant effects, but its impact on non-alcoholic fatty liver disease (NAFLD) is still controversial. The aim of this paper is to identify the relationship between tea and NAFLD by Mendelian randomisation (MR) and complete clinical validation using National Health and Nutrition Examination Survey (NHANES) database. MR used data from Genome Wide Association Study, with inverse-variance weighted (IVW) as principal analytical methods. The reliability of the results was verified by a series of sensitivity and heterogeneity tests. Subsequently, clinical validation was conducted using NHANES (2005–2018), involving 22 257 participants, grouped by the type of tea. Green tea drinkers were categorised into four groups (Q1–Q4) by quartiles of green tea intake, from lowest to highest (similar for black tea drinkers and other tea drinkers). Models were constructed by logistic regression to estimate the role of tea consumption (Q1–4) on NAFLD. Finally, using fibrosis-4 index (FIB-4) to evaluate the severity of hepatic fibrosis, the effect of tea consumption (Q1–4) on the degree of hepatic fibrosis was investigated by linear regression. IVW method (OR = 0·43, 95 % CI: 0·21, 0·85, P = 0·01) and weighted median method (OR = 0·35, 95 % CI: 0·14, 0·91, P = 0·03) revealed there was a causal relationship between tea and NAFLD. An array of sensitivity analyses validated the reliability of results. Analysis of NHANES indicated tea drinker present a slightly lower prevalence of NAFLD than non-tea drinker (green tea drinkers: 47·6 %, black tea drinkers: 46·3 %, other tea drinker: 43·2 %, non-tea drinkers: 48·1 %, P < 0·05). After adjusting for confounders, compared with the lowest black tea consumption (Q1), the population with the highest black tea consumption (Q4) was independently related to lower presence of NAFLD (Q4: OR = 0·69, 95 % CI: 0·50, 0·93, P < 0·05), such association remained stable in the overweight subgroup. As further analysed, Q4 also displayed a significant negative correlation with the level of hepatic fibrosis in patients with NAFLD (β = –0·073, 95 % CI: –0·126, −0·020, P < 0·01).Tea reduces the morbidity of NAFLD and ameliorates hepatic fibrosis degree in those already suffering from the disease.

People living with mental illness report a broad spectrum of nutrition risks, beyond malnutrition, but appropriate and adequately validated nutrition risk screening tools for mental health settings are lacking. This study aimed to develop a nutrition-risk screening tool, the NutriMental Screener, and to perform preliminary feasibility and validity testing. In an international, stakeholder engaging approach, a multifaceted nutrition-risk screening tool for mental health services was developed by means of workshops with international stakeholders and two online surveys. Feasibility of the NutriMental screener was tested as part of a research study in Switzerland with 196 participants, evenly distributed across the three study groups (sixty-seven outpatients and sixty-five inpatients with psychotic or depressive disorders as well as sixty-four controls without mental illness). The NutriMental screener consists of ten items covering different nutritional issues that indicate the need for referral to a dietitian or clinical nutritionist. Almost all patients (94·7 %) reported at least one nutrition risk by means of the NutriMental screener. Prevalence for nutrition risks via NutriMental screener was higher in patients than in controls. Almost every second patient expressed a desire for nutritional support (44·7 %). After further validity testing is completed, there is the potential for the NutriMental Screener to replace malnutrition screening tools as routine screening in various mental health settings aiming to organise nutritional therapy prescriptions in a more targeted and efficient manner.

Randomised controlled trials have demonstrated the benefit of diet modification to improve diet quality in the treatment of adult major depressive disorder (MDD). However, research examining nutritional interventions for adolescents with MDD is sparse. This pilot study examined the feasibility of a personalised nutrition intervention for adolescents with MDD. Ten adolescents with MDD and their parents recruited from a tertiary care setting participated in an 8-week, single-arm mixed-methods study. Feasibility was assessed using five criteria (demand, acceptability, implementation, adaptation and limited efficacy testing) alongside qualitative interviews. The intervention involved four bi-weekly virtual nutrition counselling sessions with a stepped approach to dietary change, menu planning, grocery delivery and educational eHealth messages. Study participants sought positive changes in diet, health and lifestyle for adolescents and family-wide benefits. Recruitment challenges included concerns about managing mood fluctuations, anticipated dietary restrictions and the potential time and effort required for diet adherence. Feedback based on interviews emphasised moderate to high acceptability, satisfaction with menu planning and counselling and recognition of the benefits of trying new foods and sustaining positive dietary changes beyond the study. Improvements in depression symptoms (Cohen’s d = 0·36, 95 % CI (–0·24, 3·36)), parent food modeling (Cohen’s d = 0·24, 95 % CI (–0·43, 1·16) and the family food environment (Cohen’s d = 0·61, 95 % CI (–0·04, 2·61)) were observed. This nutrition intervention was feasible for adolescents with MDD and was acceptable to both parents and depressed adolescents. These preliminary data suggest that further examination of the intervention and its potential benefits on depression symptoms and family food dynamics are warranted.

This study examined the efficacy of a probiotic in reducing depressive symptom severity in people with subthreshold depression. In a double-blind, randomised, placebo-controlled trial, a probiotic (1 × 10^9 live cells per strain: Limosilactobacillus fermentum LF16 (DSM26956), Lacticaseibacillus rhamnosus LR06 (DSM21981), Lactiplantibacillus plantarum LP01 (LMG P-21021) and Bifidobacterium longum 04 (DSM23233)) or placebo was taken daily for 12 weeks. Data were collected at baseline, 6 and 12 weeks including psychological symptom severity (Beck Depression Inventory, BDI; Patient Health Questionnaire, PHQ; Hospital Anxiety Depression Scale, HADS; and Depression Anxiety and Stress Scale, DASS). Biomarkers of glycaemia, inflammation (high-sensitivity C-reactive protein, hs-CRP), antioxidant status (total glutathione (GSH)) and stress (cortisol awakening response, CAR) were also measured. Thirty-nine participants (nineteen probiotic; twenty placebo) were enrolled. There were no significant between-group differences in the examined psychological symptom severity scores, despite certain significant within-group changes observed in both groups from baseline to 6 and/or 12 weeks of follow-up. Regarding biomarkers, the probiotic group showed reduced hs-CRP (–1520; 95 % CI –273·7, −2766·2 ng/dl) and CAR (–0·28; 95 % CI −0·05, −0·51 μg/dl) at 12 weeks, but increased total GSH (3·9; 95 % CI 0·1, 7·5 ng/dl) at 6 weeks, compared with the placebo. The current study reported favourable decreases in depressive symptoms in both groups. Although the within-group changes observed in the probiotic group were supported by favourable inflammatory, antioxidant status and stress biomarker changes compared with the placebo, further research is required to shed more light on the role of gut microbiota modulation on emotional regulation.

Epidemiological evidence suggests that a higher intake of sugar during pregnancy is associated with a higher risk of childhood asthma and atopy. However, randomised trial evidence supporting such a link is lacking. This study aimed to examine whether a low glycaemic index (GI) dietary intervention during pregnancy decreases the risk of childhood asthma and eczema. This is a secondary analysis of 514 children from the ROLO trial. Healthy women were randomised to receive an intervention of low GI dietary advice or routine care from early pregnancy. Mothers reported current doctor-diagnosed eczema in their children at 2 years (n 271) and current doctor-diagnosed asthma and eczema in their children at 5 (n 357) and 9–11 years (n 391) of age. Multivariable logistic regression models were used test the effect of the intervention on child outcomes overall and stratified by maternal education. There was a suggestion of a reduction in asthma at 5 years of age in children whose mothers received the low GI dietary intervention during pregnancy compared with usual care (adjusted OR 0·46 (95 % CI 0·19, 1·09); P = 0·08). In stratified adjusted analyses, the intervention was associated with a reduced risk of asthma at 5 years of age in children born to mothers with incomplete tertiary level education but not in those with complete tertiary level education (OR 0·14 (95 % CI 0·02, 0·69); P = 0·010 and OR 1·03 (95 % CI 0·34, 3·13); P = 0·94, respectively). A low GI diet in pregnancy may reduce the risk of developing asthma in childhood, particularly amongst children born to mothers with lower educational attainment.