Nutrition risk screening methods for adults living with severe mental illness: A scoping review.

AIM: Adults living with severe mental illness experience a greater burden of physical comorbidities and earlier mortality than the general population. Malnutrition, overnutrition, dysphagia, constipation and disordered eating have been observed in this population and can lead to poor nutritional status. Early identification of such conditions may reduce their impact on functional status, quality of life and health outcomes. This scoping review aimed to identify all nutrition risk screening methods published in English internationally for use with adults living with severe mental illness and ascertain which, if any, were validated for the target population. METHODS: A four-step search strategy was used to search six electronic databases and grey literature, from inception to April 2020, for articles reporting nutrition risk screening methods used in this population. Information on the content and validity of screening methods was extracted and analysed by three independent reviewers. RESULTS: Seventeen nutrition risk screening methods were identified, of which three were validated within a population of adults with severe mental illness. One screening method was found for both malnutrition and dysphagia risk, respectively, and three for constipation risk. No single method was found for overnutrition. Eleven screening methods were identified for disordered eating risk, of which two were validated for the target population. CONCLUSIONS: Nutrition risk screening methods and their validation in adults living with severe mental illness are inadequately researched. This scoping review highlights the need for future research to develop new or validate existing screening methods specifically for the target population.

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.

A feasibility study: association between gut microbiota enterotype and antibody response to seasonal trivalent influenza vaccine in adults.

Objective: We investigated the potential feasibility of a randomized controlled trial of a nutritional intervention that may alter human gut microbiota and support immune defence against respiratory tract infection in adults (Proposed Study). Methods: In total, 125 healthy adults aged 18-64 participated in a 6-month study that measured antibody response to the seasonal trivalent influenza vaccine. We assessed completion rates, procedure adherence rates and the influence of possible exclusion criteria on potential recruitment into the Proposed Study. We examined whether the gut microbiota could be categorised into enterotypes, and whether there was an association between enterotypes and the antibody response to the influenza vaccine. Results: The participant completion rate was 97.6% (95% CI 93.1-99.5%). The proportions (95% CI) of participants who may be excluded for antibiotic or corticosteroid use in the 30 days prior to the study, or due to receiving the influenza vaccine in the previous two years were 9.6% (5.1-16.2), 8.0% (3.9-14.2) and 61.6% (52.5-70.2), respectively. All participants were stratified into four gut microbiota enterotypes. There was no association between these enterotypes and the antibody response to the influenza vaccine, although the study was not powered for this outcome. Conclusion: This study design is suitable for the Proposed Study. The completion rate is likely to be high, although exclusion criteria should be selected with care. Further analyses of gut microbiota composition or function in association with antibody and immune responses are warranted to explore the role of host-microbiota interactions on protective immunity.