Prospective Observational Study to Assess Quality of Life before and after Introduction of Probiotic Nutraceuticals and Probiotic Food (Curd) in Subjects with Depression: A Comparative Analysis

INTRODUCTION

Depression a serious and widespread mental disorder affects a significant portion of the global population. It is characterized by a persistent depressed mood, a loss of interest or pleasure in activities, and can extend over prolonged periods of time. Unlike regular mood changes, depression can have a profound impact on various aspects of life, influencing relationships with family, friends, and one’s wider community. It can also disrupt performance at school and work, making it a pressing concern in public health. Notably, this condition affects more women than men, with an estimated 5% of adults worldwide grappling with depression.¹

Depression and psychological stress pose significant challenges with limited effective treatments. Recent research investigates the gut-brain axis and the potential of probiotics to impact mental health. Probiotics have been shown to reduce depressive symptoms through their anti-inflammatory effects, but further rigorous trials are necessary to confirm these findings.² The gut-brain-microbiome axis is a focal point of research, highlighting the potential of probiotics in mitigating depressive disorders.³ This complex relationship between the gut microbiota and mental health has led to the concept of “psychobiotics” that can enhance mental well-being through microbiota-modifying properties.⁴ Probiotics have historical use in addressing mental health, but only recent comprehensive clinical trials have explored their potential in treating depression.⁴

Recent fMRI studies reveal neural correlates of probiotic-induced mood improvements.⁵ One study demonstrates reduced depressive symptoms with a specific probiotic strain, supporting its therapeutic potential.⁶ Research suggests probiotics modulate inflammatory markers, linking gut health to mental well-being.⁷ Another study highlights the enteric nervous system’s role in the gut-brain axis, informing potential interventions.⁸

Understanding the potential benefits of probiotics in managing depression is of paramount importance, as it could offer new, more effective, and holistic approaches to improving the lives of individuals grappling with this debilitating condition. This study seeks to provide valuable insights into this area of research and contribute to the growing body of knowledge on the role of probiotics in mental health.

The World Health Organization (WHO) defines quality of life as an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concerns. Understanding the influence of depression and its potential alleviation through probiotics on this multi-dimensional construct is of paramount importance.⁹ Therefore, this study aims to assess the impact of probiotic nutraceuticals and probiotic food (curd) on the quality of life in individuals with depression, contributing to the ongoing exploration of probiotics as a therapeutic approach to mental health. This research seeks to bridge the gap between research and practice, offering new ways to improve the lives of individuals with depression.

MATERIALS AND METHODS

The study was conducted at MGM Medical College, Indore, with approval from the institutional ethical committee (Approval No. EC/MGM/FEB-20/63). Participants were recruited in the Outpatient Department (OPD), adhering to specified inclusion and exclusion criteria.

For accurate curd (probiotic food) volume measurement, standardized measuring glasses were provided, and participants were instructed to fill the glass to the designated volume mark. Practical demonstrations ensured correct self-measurement of the prescribed curd volume at each dose. Exclusion criteria encompassed comprehensive psychiatric assessments, structured interviews, and history checks. Individuals with other psychiatric illnesses were explicitly excluded from the study to focus on the specific condition under investigation.

Randomization was not employed in this prospective observational study. The selection of treatment groups was based on participant preferences and the availability of treatment options. To ensure medication adherence, measures included informed consent, counseling sessions, regular follow-up assessments, and medication diaries. Participants were educated about the exclusive use of the provided probiotics to discourage alternative probiotic or dietary supplement use.

RESULTS

In this study, the age groups exhibited the highest representation (32%) within the 18–30 years range and the lowest (21%) among individuals aged 40–50 years. Regarding gender distribution, the majority (53.3%) were females, while the minority (46.7%) were males. In terms of marital status, most participants (70.0%) were married, with a smaller proportion (30.0%) being unmarried. The data on religious affiliation indicated that the largest group (80.0%) identified as Hindu, whereas the smallest group (20.0%) belonged to the Muslim community. Regarding education levels, the highest representation (22.2%) was among those with a middle school certificate, and the lowest (10%) was among those with a post high school diploma.

In terms of total illness duration, the highest frequency (37.8%) of patients reported an illness duration between 1 and 6 months, followed by an equal frequency (37.8%) with illness durations exceeding 12 months. The lowest frequency (24.4%) was observed in patients with illness durations ranging from 6 to 12 months. Regarding family history of depression, the majority of patients (93.3%) did not have a recorded family history of depression, while a minority (6.7%) had a positive family history of depression.

On examination of the obtained results, it became evident that the comparison of mean WHOQOL-BREF scores among patients, taking into consideration different treatment types and the passage of time, showed statistically significant differences (p < 0.05). This statistical significance underscores the substantial impact of the interventions on the patient’s quality of life.

It was observed that the transition from day 0 to day 28 resulted in a significant increment in the WHOQOL-BREF scores, although the magnitude of change varied among the distinct treatment groups. Specifically, the probiotic group exhibited a slightly more substantial increase, with scores rising from an initial mean of 34.73 ± 1.55 on day 0 to 46.72 ± 2.47 on day 28. This observation was significant when contrasted with the changes observed in the escitalopram group, where the WHOQOL-BREF scores progressed from an initial mean of 34.58 ± 1.82 on day 0 to 42.37 ± 2.54 on day 28. Similarly, the curd group displayed a marked improvement in scores, increasing from an initial mean of 35.28 ± 1.35 on day 0 to 44.43 ± 2.36 on day 28 (Table 1).

The detailed outcomes, as presented in Table 2 suggest that patients in the probiotic group experienced a more significant improvement in their quality of life compared to those in the escitalopram and curd groups over the study period (Tables 3 and 4).

DISCUSSION

The findings of our study demonstrate that the mean scores on the WHO-BREF scale, a validated tool for assessing quality of life, exhibited a substantial improvement when comparing patients across different treatment days and various treatment types. This highlights the effectiveness of these interventions in elevating the overall quality of life experienced by our study participants.

Furthermore, our analysis revealed that the comparative assessment of mean WHO-BREF scores between different treatment days and treatment types showed statistically significant results. Notably, there were no significant variations observed when comparing the effects of each day of treatment across different treatment types.

We observed a moderate yet meaningful increase in WHO-BREF scores over the 28-day study period among participants in the probiotic group. The scores displayed a positive pattern, starting at 34.73 ± 1.55 on day 0 and improving to 46.72 ± 2.47 by day 28. In comparison, the escitalopram-only group showed an increase from 34.58 ± 1.82 on day 0 to 42.37 ± 2.54 on day 28. Similarly, the curd group displayed an increase, with scores rising from 35.28 ± 1.35 on day 0 to 44.43 ± 2.36 on day 28.

These collective outcomes signify that participants in the probiotic group show a more substantial improvement in their quality of life in comparison to their counterparts in the escitalopram and curd groups throughout the duration of our study.

Our findings align with the study done by Pinto-Sanchez MI et al.¹⁰ on patients with irritable bowel syndrome, revealing that the probiotic BL (Bifidobacterium longum) significantly reduced depression scores and enhanced quality of life. Similarly, Kommers et al.¹¹ carried out a randomized, double-blind, placebo-controlled study on female university students with intestinal constipation, demonstrating that probiotic supplementation positively impacted the quality of life.

The findings from multiple studies highlight the potential of probiotics in improving mental health and depressive symptoms. Kazemi et al.¹² reported a significant reduction in depression scores with probiotic supplementation in patients with major depressive disorder (MDD). Slykerman et al.¹³ discovered that Lactobacillus rhamnosus HN001 supplementation during pregnancy and postpartum led to lower depression and anxiety scores in mothers. Akkasheh et al.¹⁴ demonstrated that probiotic intake for 8 weeks reduced beck depression inventory scores, insulin levels, insulin resistance, and high-sensitivity C-reactive protein concentrations in MDD patients. These findings collectively suggest that probiotics may offer valuable support in alleviating depressive symptoms and enhancing mental well-being.

Additionally, several studies contribute valuable insights into the potential benefits of probiotics in individuals with MDD. Ghorbani et al.¹⁵ reported that patients receiving a symbiotic capsule (probiotic capsule plus fluoxetine) experienced a greater reduction in HAM-D scores compared to those receiving placebo (placebo plus fluoxetine). Similarly, Kazemi et al. found that probiotic supplementation containing lactobacillus and Bifidobacterium strains led to a significant improvement in beck depression inventory scores compared to placebo in individuals with MDD.¹² Moreover, a meta-analysis by Nikolova EL et al. found a beneficial effect of probiotics in patients with MDD receiving antidepressants, though not with probiotic monotherapy.¹⁶ These findings collectively emphasize the potential synergistic effects of combining probiotics with traditional antidepressant therapies and highlight the nuanced role of probiotics in augmenting mental health outcomes in individuals with MDD.

The reasons behind these improvements in the probiotic and curd groups are multifaceted. Notably, probiotic intake may contribute to better gut health. The reintroduction or supplementation of probiotic bacteria in the gut, facilitated through dietary means, may have positive effects. Such interventions can potentially activate the hypothalamic-pituitary axis via the vagus nerve, reducing stress.¹⁷ Furthermore, probiotic bacteria may lead to increased production of serotonin and other neurohormones.¹⁸ These mechanisms offer a promising pathway to enhance quality of life, making them particularly valuable in the context of depression treatment.

The statistically significant differences in mean WHO-BREF scores between patients at the beginning and end of the 28-day treatment period could be attributed to the consistent administration of escitalopram, a well-established SSRI in depression treatment, across all treatment groups.¹⁹

Study has shed light on the promising potential of probiotics and curd as valuable adjuncts to traditional treatments for MDD. Future studies should investigate the long-term effects of probiotics and curd supplementation on the quality of life of patients with MDD. Additionally, studies should explore the optimal dosage and duration of treatment for these interventions.

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