1. Introduction
Depressive, ’ mental functioning (reduction, mood disorders, mineral deficiencies, mental deterioration, depressive symptoms
(1) Background: studies have shown that some patients experience mental deterioration after bariatric surgery. (2) Methods: We examined whether the use of probiotics and improved eating habits can improve the mental health of people who suffered from mood disorders after bariatric surgery. We also analyzed patients’ mental states, eating habits and microbiota. (3) Results: Depressive symptoms were observed in 45% of 200 bariatric patients. After 5 weeks, we noted an improvement in patients’ mental functioning (reduction in BDI and HRSD), but it was not related to the probiotic used. The consumption of vegetables and whole grain cereals increased (DQI-I adequacy), the consumption of simple sugars and SFA decreased (moderation DQI-I), and the consumption of monounsaturated fatty acids increased it. In the feces of patients after RYGB, there was a significantly higher abundance of two members of the Muribaculaceae family, namely Veillonella and Roseburia, while those after SG had more Christensenellaceae R-7 group, Subdoligranulum, Oscillibacter, and UCG-005. (4) Conclusions: the noted differences in the composition of the gut microbiota (RYGB vs. SG) may be one of the determinants of the proper functioning of the gut–brain microbiota axis, although there is currently a need for further research into this topic using a larger group of patients and different probiotic doses.The benefits of bariatric surgery include improvements in psychosocial status, social relationships, and quality of life [One of the factors affecting mental state and mood is gut microbiota [The nutritional status of an organism is also important for proper psychological functioning. For post-bariatric surgery patients, an energy-dense diet with large amounts of vegetables and fruits and restricting the consumption of highly processed products, saturated fatty acids (SFA), and simple sugars is recommended. In addition, consuming an adequate amount of protein is crucial, which is estimated to be 60–80 g/day. Dairy products, eggs, fish, lean meat, and the seeds of legumes are recommended as the main sources of protein. Equally important is the consumption of complex carbohydrates that provide fiber, as well as adequate vitamin and mineral intake [Unfortunately, despite these recommendations, protein, vitamin, and mineral deficiencies are diagnosed in many patients after bariatric surgery. The main causes are insufficient consumption of individual food components, the development of food aversion, a lack of recommended nutritional supplementation, decreased secretion of hydrochloric acid in the stomach, bypassing a part of the intestine that allows absorption of nutrients, and gastrointestinal concomitants [To the best of our current knowledge, there are few scientific studies addressing the relationship between dietary changes, intestinal barrier functioning, and worsening mental status in patients after bariatric surgery. The aim of the study was to evaluate the efficacy of a five week probiotic therapy with multistrain probiotic preparation (Sanprobi Barrier) and the introduction of a balanced diet to improve the mental performance of patients ≥6 months after bariatric surgery who suffered from mood disorders. The multi-strain probiotic used in the previous study, showed both a reduction in depressive symptoms [