Ketogenic diet for depression: A potential dietary regimen to maintain euthymia?

Approximately 30% of patients with major depressive disorder (MDD) present resistance to current pharmacological therapies. There is the possibility that an appropriate nutritional regimen can maintain euthymia. Poor dietary pattern and lack of nutritional knowledge are common among today's population; nutrient-rich foods are being replaced by highly processed foods that lead to a higher risk of developing chronic diseases such as metabolic syndrome, hypercholesterolemia, and diabetes. There is growing evidence of the beneficial role of vitamins and dietary supplements for improving symptoms in a range of affective disorders by regulating the gut microbiome, gut-brain axis, and neurotransmitter levels. Reduced GABA neurotransmission is regularly observed in MDD. Moreover, positive allosteric GABA modulators (i.e benzodiazepines) are widely prescribed to alleviate depression symptoms, but their use needs to be limited, as it can lead to addiction. An alternative option may be the adherence to a ketogenic diet, which consists of low-carbohydrate, moderate-protein, and high-fat intake. It is mainly known for its beneficial role in weight-loss, refractory epilepsy treatment, and balancing glucose levels. A ketogenic diet can also increase GABA levels to aid the mechanism of action of monoaminergic drugs. Thus, it could potentially be used in the treatment for affective disorders due to its potential role in GABA/glutamate balance. While more research is needed before this regimen can be regularly recommended to patients, here we discuss evidence that may encourage physicians to prescribe ketogenic diet as an adjuvant for patients receiving psychotherapy and pharmacology.

The intervention of unique plant polysaccharides - Dietary fiber on depression from the gut-brain axis.

As an invisible organ of human body, the gut microbiota plays an important role in human life and has become a hot spot in the field of life science in recent years. Due to the increasing pressure of work and life, people are prone to depression. The in-depth mechanism studies indicated that the gut microbiota could improve the depression symptom through the gut-brain axis (GBA). As unique plant polysaccharides, dietary fiber can effectively modulate the intestinal flora disorders and its crucial role in orchestrating host-microbiota crosstalk has been confirmed. This review highlights the mechanisms that the gut microbiota affects the development of depression through GBA and focuses on dietary fiber intervention on the improvement of intestinal microbiota imbalance, which may provide new ideas for the prevention and treatment of depression.

Lipid Profile, Lipoprotein Subfractions, and Fluidity of Membranes in Children and Adolescents with Depressive Disorder: Effect of Omega-3 Fatty Acids in a Double-Blind Randomized Controlled Study.

Depressive disorder (DD) is a psychiatric disorder whose molecular basis is not fully understood. It is assumed that reduced consumption of fish and omega-3 fatty acids (FA) is associated with DD. Other lipids such as total cholesterol (TCH), LDL-, and HDL-cholesterols (LDL-CH, HDL-CH) also play a role in depression. The primary endpoint of the study was the effect of omega-3 FA on the severity of depression in children and adolescents. This study aimed to investigate the secondary endpoint, relationship between depressive disorder symptoms and lipid profile, LDL- and HDL-cholesterol subfractions, Paraoxonase 1 (PON1) activities, and erythrocyte membrane fluidity in 58 depressed children and adolescents (calculated by the statistical program on the effect size), as well as the effect of omega-3 FA on the monitored parameters. Depressive symptoms were assessed by the Children's Depression Inventory (CDI), lipid profile by standard biochemical procedures, and LDL- and HDL-subfractions by the Lipoprint system. Basic biochemical parameters including lipid profile were compared with levels in 20 healthy children and were in the physiological range. Improvement of symptoms in the group supplemented with a fish oil emulsion rich in omega-3 FA in contrast to omega-6 FA (emulsion of sunflower oil) has been observed. We are the first to report that omega-3 FAs, but not omega-6 FA, increase large HDL subfractions (anti-atherogenic) after 12 weeks of supplementation and decrease small HDL subfractions (proatherogenic) in depressed children. We found a negative correlation between CDI score and HDL-CH and the large HDL subfraction, but not LDL-CH subfractions. CDI score was not associated with erythrocyte membrane fluidity. Our results suggest that HDL-CH and its subfractions, but not LDL-CH may play a role in the pathophysiology of depressive disorder. The study was registered under ISRCTN81655012.

Dietary supplementation with Lactobacillus rhamnosus JB-1 restores brain neurochemical balance and mitigates the progression of mood disorder in a rat model of chronic unpredictable mild stress.

Major depressive disorder is a stress-related disease associated with brain metabolic dysregulation in the glutamine-glutamate/γ-aminobutyric acid (Gln-Glu/GABA) cycle. Recent studies have demonstrated that microbiome-gut-brain interactions have the potential to influence mental health. The hypothesis of this study was that Lactobacillus rhamnosus JB-1 (LR-JB1™) dietary supplementation has a positive impact on neuro-metabolism which can be quantified in vivo using magnetic resonance spectroscopy (MRS). A rat model of depressive-like disorder, chronic unpredictable mild stress (CUMS), was used. Baseline comparisons of MRS and behavior were obtained in a control group and in a stressed group subjected to CUMS. Of the 22 metabolites measured using MRS, stressed rats had significantly lower concentrations of GABA, glutamate, glutamine + glutathione, glutamate + glutamine, total creatine, and total N-acetylaspartate (tNAA). Stressed rats were then separated into 2 groups and supplemented with either LR-JB1™ or placebo and re-evaluated after 4 weeks of continued CUMS. The LR-JB1™ microbiotic diet restored these metabolites to levels previously observed in controls, while the placebo diet resulted in further significant decrease of glutamate, total choline, and tNAA. LR-JB1™ treated animals also exhibited calmer and more relaxed behavior, as compared with placebo treated animals. In summary, significant cerebral biochemical downregulation of major brain metabolites following prolonged stress were measured in vivo using MRS, and these decreases were reversed using a microbiotic dietary supplement of LR-JB1™, even in the presence of continued stress, which also resulted in a reduction of stress-induced behavior in a rat model of depressive-like disorder.

Oral Administration of S-Adenosylmethionine (SAMe) and Lactobacillus Plantarum HEAL9 Improves the Mild-To-Moderate Symptoms of Depression: A Randomized, Double-Blind, Placebo-Controlled Study.

OBJECTIVE: To assess the effects of the combination of SAMe (S-adenosylmethionine) 200 mg and Lactobacillus plantarum (L. plantarum) HEAL9 1 × 109 CFU for the overall symptomatology of mild-to-moderate depression. METHODS: This 6-week randomized, double-blind, placebo-controlled study included subjects aged 18-60 years with mild-to-moderate depression (according to ICD-10 diagnostic criteria) recruited from September 17, 2018, to October 5, 2018. Difference between groups in change from baseline to treatment week 6 on the Zung Self-Rating Depression Scale (Z-SDS) was the primary outcome. Comparisons between groups in change from baseline to treatment week 2 of the Z-SDS and from baseline to treatment weeks 2 and 6 of other scales (related to insomnia, anxiety, irritable bowel syndrome, and health status) were also analyzed. RESULTS: Ninety patients were randomized to SAMe plus L. plantarum HEAL9 (n = 46) or placebo (n = 44) groups. A greater reduction for the new combination compared to placebo was seen at treatment week 6 in the Z-SDS total score (P = .0165) and the core depression subdomain (P = .0247). A significant reduction in favor of the combination was shown at treatment week 2 for the Z-SDS total score (P = .0330), the cognitive and anxiety subdomains (P = .0133 and P = .0459, respectively), and the anxiety questionnaire (P = .0345). No treatment-related adverse events occurred. CONCLUSIONS: Supplementation of SAMe and L. plantarum HEAL9 in adults with subthreshold or mild-to-moderate symptoms of depression resulted in fast and clinically relevant effects after 2 weeks. The combination was safe and significantly improved symptoms of depression, anxiety, and cognitive and somatic components. The effect of this novel product is independent from the severity of the symptoms unlike traditional antidepressants available on the market that have minimal benefits for subthreshold or mild-to-moderate symptoms. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03932474.

Flavonoid-Rich Orange Juice Intake and Altered Gut Microbiome in Young Adults with Depressive Symptom: A Randomized Controlled Study.

Depression is not just a general mental health problem but a serious medical illness that can worsen without treatment. The gut microbiome plays a major role in the two-way communication system between the intestines and brain. The current study examined the effects of flavonoids on depression by observing the changes in the gut microbiome and depressive symptoms of young participants consuming flavonoid-rich orange juice. The depressive symptom was assessed using the Center for Epidemiological Studies Depression Scale (CES-D), a psychiatric screening tool used to detect preexisting mental disorders. The study population was randomly divided into two groups: the flavonoid-rich orange juice (FR) and an equicaloric flavonoid-low orange cordial (FL) group. For 8 weeks, participants consumed FR (serving a daily 380 mL, 600 ± 5.4 mg flavonoids) or FL (serving a daily 380 mL, 108 ± 2.6 mg flavonoids). In total, 80 fecal samples from 40 participants (mean age, 21.83 years) were sequenced. Regarding depression, we observed positive correlations between brain-derived neurotrophic factor (BDNF) and the Lachnospiraceae family (Lachnospiraceae_uc and Murimonas) before flavonoid orange juice treatment. Most notably, the abundance of the Lachnospiraceae family (Lachnospiraceae_uc, Eubacterium_g4, Roseburia_uc, Coprococcus_g2_uc, Agathobacter_uc) increased after FR treatment compared to that after FL treatment. We also validated the presence of unclassified Lachnospiraceae through sensitive real-time quantitative polymerase chain reaction using stool samples from participants before and after flavonoid treatment. Our results provide novel interventional evidence that alteration in the microbiome due to flavonoid treatment is related to a potential improvement in depression in young adults.

Effects of a multicomponent exercise program combined with calcium-vitamin D3-enriched milk on health-related quality of life and depressive symptoms in older men: secondary analysis of a randomized controlled trial.

PURPOSE: Osteoporosis is associated with both lower health-related quality of life and depression in older people. We examined the independent and combined effects of a multi-component exercise program and calcium-vitamin D3 fortified milk on health-related quality of life (HR-QoL) and depression in older men. METHODS: In this 12-month, factorial design randomized controlled trial, 180 healthy community-dwelling men aged 50-79 years with normal to below average bone mineral density were allocated into one of four groups: exercise + fortified milk; exercise; fortified milk; or controls. Exercise consisted of high-intensity resistance training with weight-bearing exercise (3 days per week; 60-75 min per session). Men assigned to fortified milk consumed 400 ml/day of low-fat milk containing 1000 mg/day calcium and 800IU/day vitamin D3. Questionnaires were used to assess HR-QoL (SF-36) and depressive symptoms (Center for Epidemiologic Studies Depression Scale) at baseline, and 6 and 12 months. A linear mixed model analysis was used to test whether there was a synergistic interaction between exercise and calcium-vitamin D3. If no significant interactions were detected, the main effects of exercise and fortified milk were examined. RESULTS: Mean adherence to the exercise program and fortified milk was 67% (95% CI 61, 73%) and 90% (95% CI 86, 93%), respectively. There were no exercise-by-fortified milk interactions nor main effects of exercise or calcium-vitamin D for any of the HR-QoL measures or depressive symptoms. CONCLUSION: In healthy community-dwelling older men, exercise training and/or calcium-vitamin D fortified milk did not improve HR-QoL or depressive symptoms.

Fermented foods, the gut and mental health: a mechanistic overview with implications for depression and anxiety.

Mental disorders including depression and anxiety are often comorbid with gut problems, suggesting a bidirectional relationship between mental health and gut function. Several mechanisms might explain this comorbidity, such as inflammation and immune activation; intestinal permeability; perturbations in the hypothalamic-pituitary-adrenal axis; neurotransmitter/neuropeptide dysregulation; dietary deficiencies; and disturbed gut microbiome composition. The potential of modulating the microbiome-gut-brain axis, and subsequently mental health, through the use of functional foods, is an emerging and novel topic of interest. Fermented foods are considered functional foods due to their putative health benefits. The process of microbial fermentation converts food substrates into more nutritionally and functionally rich products, resulting in functional microorganisms (probiotics), substrates that enhance proliferation of beneficial bacteria in the gut (prebiotics), and bioactive components (biogenics). These functional ingredients act biologically in the gastrointestinal tract and have the ability to modify the gut microbiota, influence translocation of endotoxins and subsequent immune activation, and promote host nutrition. This narrative review explores the theoretical potential of the functional components present in fermented foods to alter gut physiology and to impact the biological mechanisms thought to underpin depression and anxiety. Pre-clinical studies indicate the benefits of fermented foods in relieving perturbed gut function and for animal models of depression and anxiety. However, in humans, the literature relating to the relevance of fermented food for treating or preventing depression and anxiety is sparse, heterogeneous and has significant limitations. This review identifies a critical research gap for further evaluation of fermented foods in the management of depression anxiety in humans.

Adherence to the MIND diet and prevalence of psychological disorders in adults.

BACKGROUND: There is no study that examined the association of the MIND diet and odds of psychological disorders. We investigated the association between adherence to the MIND diet and odds of psychological disorders. METHODS: A total of 3176 adults were included in this cross-sectional study. Dietary intakes of study participants were collected using a validated dish-based 106-item semi-quantitative food frequency questionnaire (DS-FFQ). The MIND diet score was calculated based on participants' dietary intakes obtained from DS-FFQ. To assess depression and anxiety, the Iranian validated version of Hospital Anxiety and Depression Scale (HADS) was used. Psychological distress was examined using General Health Questionnaire (GHQ). RESULTS: After taking potential confounders into account, participants in the highest quartile of the MIND diet score had a lower odds of depression (OR: 0.68; 95% CI: 0.53-0.89) and psychological distress (OR: 0.68; 95% CI: 0.52-0.89) than those in the lowest quartile. No significant association was observed between consumption of MIND diet and odds of anxiety (OR: 0.72; 95% CI: 0.51-1.03). When we did gender-stratified analyses, no significant association was seen between adherence to the MIND diet and odds of psychological disorders in men; however, women in the top quartile of the MIND diet score had lower odds of depression (OR: 0.60; 95% CI: 0.45-0.81) and psychological distress (OR: 0.66; 95% CI: 0.48-0.90) than those in the bottom quartile. CONCLUSION: We found that greater adherence to the MIND diet was inversely associated with odds of depression and psychological distress. No significant association was observed between consumption of MIND diet and odds of anxiety.

Prebiotics and probiotics for depression and anxiety: A systematic review and meta-analysis of controlled clinical trials.

With growing interest in the gut microbiome, prebiotics and probiotics have received considerable attention as potential treatments for depression and anxiety. We conducted a random-effects meta-analysis of 34 controlled clinical trials evaluating the effects of prebiotics and probiotics on depression and anxiety. Prebiotics did not differ from placebo for depression (d = -.08, p = .51) or anxiety (d = .12, p = .11). Probiotics yielded small but significant effects for depression (d = -.24, p < .01) and anxiety (d = -.10, p = .03). Sample type was a moderator for probiotics and depression, with a larger effect observed for clinical/medical samples (d = -.45, p < .001) than community ones. This effect increased to medium-to-large in a preliminary analysis restricted to psychiatric samples (d = -.73, p < .001). There is general support for antidepressant and anxiolytic effects of probiotics, but the pooled effects were reduced by the paucity of trials with clinical samples. Additional randomized clinical trials with psychiatric samples are necessary fully to evaluate their therapeutic potential.

Preventing the recurrence of depression with a Mediterranean diet supplemented with extra-virgin olive oil. The PREDI-DEP trial: study protocol.

BACKGROUND: The role of dietary patterns in the prevention of unipolar depression has been analyzed in several epidemiological studies. The primary aims of this study are to determine the effectiveness of an extra-olive oil-enriched Mediterranean diet in reducing the recurrence of depression and improving the symptoms of this condition. METHODS: Multicenter, two-arm, parallel-group clinical trial. Arm 1, extra-virgin olive oil Mediterranean diet; Arm 2, control group without nutritional intervention. Dieticians are in charge of the nutritional intervention and regular contact with the participants. Contacts are made through our web platform ( https://predidep.es/participantes/ ) or by phone. Recurrence of depression is assessed by psychiatrists and clinical psychologists through clinical evaluations (semi-structured clinical interviews: Spanish SCID-I). Depressive symptoms are assessed with the Beck Depression Inventory. Information on quality of life, level of physical activity, dietary habits, and blood, urine and stool samples are collected after the subject has agreed to participate in the study and once a year. DISCUSSION: To the best of our knowledge, the PREDI-DEP trial is the first ongoing randomized clinical trial designed to assess the role of the Mediterranean diet in the prevention of recurrent depression. It could be a cost-effective approach to avoid recurrence and improve the quality of life of these patients. TRIAL REGISTRATION: The study has been prospectively registered in the U.S. National Library of Medicine ( https://clinicaltrials.gov ) with NCT number: NCT03081065.

The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: Poor diet can be detrimental to mental health. However, the overall evidence for the effects of dietary interventions on mood and mental well-being has yet to be assessed. We conducted a systematic review and meta-analysis examining effects of dietary interventions on symptoms of depression and anxiety. METHODS: Major electronic databases were searched through March 2018 for all randomized controlled trials of dietary interventions reporting changes in symptoms of depression and/or anxiety in clinical and nonclinical populations. Random-effects meta-analyses were conducted to determine effect sizes (Hedges' g with 95% confidence intervals [CI]) for dietary interventions compared with control conditions. Potential sources of heterogeneity were explored using subgroups and meta-regression analyses. RESULTS: Results: Sixteen eligible randomized controlled trials (published in English) with outcome data for 45,826 participants were included; the majority of which examined samples with nonclinical depression (n = 15 studies). Nonetheless, dietary interventions significantly reduced depressive symptoms (g = 0.162, 95% CI = 0.055 to 0.269, p = 0.003). Similar effects were observed among high-quality trials (g = 0.171, 95% C.I.=0.057 to 0.286, p=0.003) and when compared with both inactive (g = 0.114, 95% C.I.=0.008 to 0.219, p=0.035) and active controls (g = 0.224, 95% C.I.= 0.052 to 0.397, p = 0.011). No effect of dietary interventions was observed for anxiety (k = 11, n = 2270, g = 0.085, 95% C.I. = -0.031 to 0.202, p=0.151). Studies with female samples observed significantly greater benefits from dietary interventions, for symptoms of both depression and anxiety. CONCLUSIONS: Dietary interventions hold promise as a novel intervention for reducing symptoms of depression across the population. Future research is required to determine the specific components of dietary interventions that improve mental health, explore underlying mechanisms, and establish effective schemes for delivering these interventions in clinical and public health settings. REGISTRATION: PROSPERO Online Protocol: CRD42018091256.

Adherence to a healthy dietary pattern is associated with less severe depressive symptoms among adolescent girls.

There is growing interest on the impact of diet on depressive disorders. However, there are limited data on the association between dietary patterns and depression symptoms among Iranian adolescents. The aim of this study was to evaluate the association between dietary patterns and depression score among Iranian adolescent girls. Data were obtained from 750 adolescent girls, who were recruited from several schools using a random cluster sampling. Dietary data were collected using a valid and reliable food frequency questionnaire (FFQ). Beck's depression inventory (BDI-II) was used to assess depression severity score. The prevalence of girls diagnosed with depression was 29.1%. Three major dietary patterns were identified in the study based on factor analysis: "Healthy", "Traditional" and "Western". The multivariate-adjusted odds ratio of having depressive symptoms was 0.55 (95% confidence intervals, 0.34-0.89) for the highest versus lowest quartile of the healthy dietary pattern score. However, there were no significant associations between the Traditional and Western dietary patterns and depression symptoms. Our results indicate that adherence to a Healthy dietary pattern characterized by high intakes of fruits, vegetables, fish and dairy products is associated with a lower probability of having depressive symptoms among Iranian adolescent girls.

Does the MIND diet decrease depression risk? A comparison with Mediterranean diet in the SUN cohort.

PURPOSE: To prospectively evaluate the association of the Mediterranean-DASH diet intervention for neurodegenerative delay (MIND) diet and the Mediterranean diet (and their components), and depression risk. METHODS: We followed-up (median 10.4 years) 15,980 adults initially free of depression at baseline or in the first 2 years of follow-up. Food consumption was measured at baseline through a validated food-frequency questionnaire, and was used to compute adherence to the MIND and the Mediterranean diets. Relationships between these two diets and incident depression were assessed through Cox regression models. RESULTS: We identified 666 cases of incident depression. Comparing the highest versus the lowest quartiles of adherence, we found no association of the MIND diet and incident depression. This relation was statistically significant for the Mediterranean diet {hazard ratio (HR) 0.75, [95% confidence interval (95% CI) 0.61, 0.94]; p < 0.01}, although with departure from linearity. A reduced depression risk was associated with higher consumption of both fruits and nuts [HR 0.82 (95% CI 0.69, 0.96); p = 0.02], moderate nuts consumption [HR 0.77 (95% CI 0.64, 0.93); p = 0.01], and avoidance of fast/fried food [HR 0.63 (95% CI 0.41, 0.96); p = 0.03]. CONCLUSIONS: The Mediterranean diet was associated with reduced depression risk, but we found no evidence of such an association for the MIND diet.

Effect of probiotic interventions on depressive symptoms: A narrative review evaluating systematic reviews.

Depression is one of the most prevalent mental illnesses and is often associated with various other medical disorders. Since the 1980s, the primary pharmacological treatment has been antidepressants, but due to the recent discovery of the association between the gut microbiome and mental health, probiotics have been proposed as an adjunctive or alternate treatment. In this narrative review, we aim to provide a holistic perspective by synthesizing and evaluating existing evidence, discussing key biological mechanisms, exploring the history of probiotic use, and appreciating the influence of modern diet on mental health. Five online databases were searched for relevant studies up to December 2017. Systematic reviews that included randomized controlled trials assessing the efficacy of probiotics in the treatment of depressive symptoms were included. Seven systematic reviews met the inclusion criteria. Three of these reviews conducted meta-analyses, out of which, two concluded that probiotics improved depressive symptoms in the sample population. Out of the four reviews that conducted qualitative analysis, three reviews concluded that probiotics have the potential to be used as a treatment. Due to the differences in clinical trials, a definitive effect of probiotics on depressive symptoms cannot be concluded. Nonetheless, probiotics seem to potentially produce a significant therapeutic effect for subjects with pre-existing depressive symptoms. Further studies are warranted for definitive conclusions.

An anti-inflammatory diet as a potential intervention for depressive disorders: A systematic review and meta-analysis.

BACKGROUND & AIMS: There is a large body of evidence which supports the role of inflammation in the pathophysiology of mental health disorders, including depression. Dietary patterns have been shown to modulate the inflammatory state, thus highlighting their potential as a therapeutic tool in disorders with an inflammatory basis. Here we conduct a systematic review and meta-analysis of current literature addressing whether there is a link between the inflammatory potential of a diet and risk of depression or depressive symptoms. METHODS: A systematic literature search was performed to identify studies that reported an association between the inflammatory potential of the diet and risk of depressive symptoms or diagnosis of depression. Random effect models were used to meta-analyse effect sizes. Quality assessment, publication bias, sensitivity and subgroup analyses were also performed. RESULTS: Eleven studies, with a total of 101,950 participants at baseline (age range: 16-72 years old), were eligible for review. A significant association between a pro-inflammatory diet and increased risk of depression diagnosis or symptoms was evident, relative to those on an anti-inflammatory diet (OR: 1.40, 95% confidence intervals: 1.21-1.62, P < 0.001). No publication bias was detected; however, some study heterogeneity was evident (I2 = 63%, P < 0.001). Subgroup analyses suggested the main source of study heterogeneity was the study design (cross-sectional or longitudinal) and the effect measure used (odds ratio, hazard ratio or relative risk). CONCLUSION: These results provide an association between pro-inflammatory diet and risk of depression. Thus, adopting an anti-inflammatory diet may be an effective intervention or preventative means of reducing depression risk and symptoms.

Recent Advances in Nutrition for the Treatment of Depressive Disorder.

Depression is one of the leading causes of disability in the world. Current pharmaceutical treatment for depression remains unsatisfactory due to its limited therapeutic efficacy and undesirable side effects. There is increasing interest in looking for alternative strategies from diet for the treatment of depressive disorder. The nutrition factors have the potential to regulate several neurochemical pathways implicated in depression. This review gives an overview of the recent advances in depression treatment using nutrition factors including vitamins, polyunsaturated fatty acid, elements and natural products. The review covers most recent publications from 2016 to mid-2018. The results of basic experimental and clinical studies were summarized. The risk of deficiency and effect of intervention using nutrition factors for the depression were also discussed. Although the results are controversial in some cases due to the experimental design, the relationship has been observed between deficiency of certain nutrition factors and incidence of depression in the majority of studies. The dietary nutrition supplements may play significant or synergic role in treating or improving depressive disorders.

Beneficial psychological effects of novel psychobiotics in diabetic rats: the interaction among the gut, blood and amygdala.

Type 2 diabetes mellitus (T2DM) can lead to major complications such as psychiatric disorders which include depressive and anxiety-like behaviors. The association of the gut-brain axis in the development of such disorders, especially in T2DM, has been elucidated; however, gut dysbiosis is also reported in patients with T2DM. Hence, the regulation of the gut-brain axis, in particular, the gut-amygdala, as a vital region for the regulation of behavior is essential. Thirty-five male Wistar rats were divided into six groups. To induce T2DM, treatment groups received high-fat diet and 35 mg/kg streptozotocin. Then, supplements of Lactobacillus plantarum, inulin or their combination were administered to each group for 8 weeks. Finally, the rats were sacrificed for measurement of blood and tissue parameters after behavioral testing. The findings demonstrated the favorable effects of the psychobiotics (L. plantarum, inulin or their combination) on oxidative markers of the blood and amygdala (superoxide dismutase, glutathione peroxidase, malondialdehyde and total antioxidant capacity), as well as on concentrations of amygdala serotonin and brain-derived neurotrophic factor, in the diabetic rats. In addition, beneficial effects were observed on the elevated plus maze and forced swimming tests with no change in locomotor activity of the rats. There was a strong correlation between the blood and amygdala oxidative markers, insulin and fasting blood sugar with depressive and anxiety-like behaviors. Our results identified L. plantarum ATCC 8014 and inulin or their combination as novel psychobiotics that could improve the systemic and nervous antioxidant status and improve amygdala performance and beneficial psychotropic effects.

Mediterranean Diet, Food Consumption and Risk of Late-Life Depression: The Mugello Study.

OBJECTIVES: To investigate eating habits and adherence to Mediterranean Diet (MD) in relation to the risk of depression in a cohort of nonagenarians enrolled within the Mugello Study, an epidemiological study aimed at investigating both clinically relevant geriatric items and various health issues, including those related to nutritional status. DESIGN: Cross-sectional study. SETTING: Homes and nursing homes in the Mugello area, Florence, Italy. PARTICIPANTS: Subjects aged 90-99 years [N=388 (271F; 117M) mean age: 92.7±3.1]. MEASUREMENTS: All subjects were evaluated through questionnaires and instrumental examinations. Adherence to MD was assessed through the Mediterranean Diet Score. A shorter version of the Geriatric Depression Scale (GDS) was used to detect the possible presence of depressive symptoms. In addition, cognitive and functional status was assessed using the Mini-Mental State Examination, the Clock Drawing Test, as well as the Basic and Instrumental Activities of Daily Living test. RESULTS: Depressed subjects (DS) (GDS score≥5, 43.8%) were older, females and widows, than non-depressed subjects (NDS). DS reported a slightly but not statistically significant lower MD score than NDS (33.9±3.9 vs. 34.6±3.3, p=0.149). Subjects who reported to consume a greater amount of olive oil and fruit were associated with a lower risk of depression (OR=0.35, 95%CI=0.20-0.59, p<0.001 and OR=0.46, 95%CI=0.26-0.84, p=0.011, respectively) after adjustment for many possible confounders. Similar results were obtained for women, while no statistically significant differences emerged for men. CONCLUSION: Our results support the hypothesis that a diet rich in olive oil and fruit, characteristics of MD, may protect against the development of depressive symptoms in older age.