Sonja Lackner

Background: The gut microbiome plays a central role in human health and is strongly influenced by diet. Probiotics can beneficially modulate the microbiome and, through the gut–brain axis, may affect mood, appetite, and food preferences. This randomized controlled trial examined whether three months of probiotic supplementation could alter dietary intake in individuals with major depression ( MD ) and healthy controls ( HC ). Methods: In this double-blind, placebo-controlled trial, 53 participants (23 with MD , 30 HC ) received either a multi-strain probiotic or placebo twice daily for three months. Dietary intake was assessed at baseline and three follow-ups using the Vienna Food Record (VFR). Nutritional data were analyzed with nut.s® software and evaluated using mixed ANOVAs for repeated measures. These analyses represent additional data collected within the framework of the ProBioHRV study. Results: Changes across dietary measures were generally small, with only a limited number reaching statistical significance. Significant three-way interactions ( time × intervention × diagnosis ) emerged for vitamin D intake, dietary variety, folic acid, and diversity. In HC , probiotic supplementation was associated with higher vitamin D intake after one week, while in MD , a similar increase was observed after three months (trend level, p = .058). Conversely, participants receiving probiotics showed lower dietary variety and diversity scores at several time points. Across all time points, folic acid intake was lower in MD compared to HC , independent of intervention. Conclusion: Probiotic supplementation did not produce consistent changes in nutrient intake but showed exploratory, time- and group-dependent patterns for selected measures, including vitamin D intake and dietary variety and diversity. Given the pilot nature of the study, these findings are descriptive and hypothesis- generating. Larger, well-powered studies with objective nutritional and microbiome measures are required.

Carotenoids are plant‐derived bioactive compounds with antioxidant properties and well‐established roles in human health. Circulating carotenoid concentrations are widely used as an objective biomarker of fruit and vegetable intake; however, their assessment by high‐performance liquid chromatography (HPLC) requires invasive sampling and laboratory infrastructure. Reflection spectroscopy–based devices, such as the Veggie Meter and Biozoom, offer rapid, noninvasive alternatives for assessing cutaneous carotenoids (CC), but their validity across different body composition profiles remains insufficiently characterized. In this study, plasma carotenoid concentrations quantified by HPLC were compared with CC measurements obtained using the Veggie Meter and Biozoom in 54 healthy women across three study visits ( n = 151 observations). Associations between plasma and cutaneous carotenoids were evaluated using Spearman and partial correlation analyses with adjustment for body fat percentage and were further examined using linear mixed‐effects models (LMMs) accounting for repeated measurements including body fat percentage and smoking status as covariates. Total plasma carotenoid concentrations were strongly correlated with CC values measured by Biozoom ( r _s (151) = 0.697, p < 0.001) and Veggie Meter ( r _s (151) = 0.650, p < 0.001). Provitamin A carotenoids exhibited the strongest associations, whereas lutein and lycopene showed weaker correlations. All associations remained statistically significant after adjusting for body fat percentage and smoking status. Both plasma and cutaneous carotenoid levels were inversely associated with BMI and obesity‐related measures (all p < 0.0033, after Bonferroni correction for multiple comparisons). These findings support the use of reflection spectroscopy–based cutaneous carotenoid measurements as valid, noninvasive nutritional biomarkers of fruit and vegetable–derived carotenoid exposure. Such tools may facilitate dietary assessment and monitoring in nutrition research, clinical practice, and public health settings, provided that body composition is considered when interpreting results.

Background: Psychiatric and psychosomatic conditions are prevalent, disabling, and frequently resistant to standard treatments. Nutrition-focused care represents an emerging integrative approach, but clinical evidence remains scarce. The outpatient department for Nutritional Psychiatry and Nutritional Psychosomatics (NP) at the Medical University of Graz was established as a pilot project, offering add-on therapy with targeted nutritional counseling, nutrient substitution and supplementation, and interventions aiming to improve the gut–brain axis. Methods: This prospective, monocentric, observational study will include approximately 84 new patients aged 18–65 over a 12-month period. Participants will complete online questionnaires at baseline and every 3 months, while routine blood samples will assess inflammatory and metabolic markers. The primary outcome is change in perceived stress, measured by the Perceived Stress Scale (PSS-10). Secondary outcomes include resilience, quality of life (SF-12, EQ-5D-5L), somatic symptoms (SSS-8), dietary habits (REAP-S v.2), psychodynamic structure (OPD-SFK), patient satisfaction, health literacy, and biomarker changes. Discussion: This study will provide the first systematic evaluation of a specialized outpatient clinic for Nutritional Psychiatry and Psychosomatics in Europe. Findings will inform the potential of nutrition-focused interventions as part of routine psychiatric and psychosomatic care and may contribute to the development of personalized, integrative treatment strategies. Trial registration: ClinicalTrials.gov NCT07050342 This study was prospectively registered at ClinicalTrials.gov (Identifier: NCT07050342), register date: 2025-06-24.