A Review on Assessment of Probiotics Impact on Quality of Life in Elderly Population Using Whoqol-Bref Scale

Aging is a natural and ongoing part of life, where the body gradually changes over time. It's a process every living being goes through, marked by physical, functional, and sometimes cognitive shifts that reflect the passage of time. In humans, it involves the progressive decline in physiological function, cellular repair, and regeneration. This can lead to increased vulnerability to diseases, decreased physical, mental, social and cognitive abilities, and ultimately leads to death ^[1]. Conditions linked to aging can lead to a decline in physical, social, cognitive and mental functions, impair the ability to carry out daily activities, and result in the loss of roles within the society and personal contentment ^[2]. Elderly population often face multiple chronic conditions, functional limitations, and age-related physiological changes that significantly impact their quality of life. Targeting this group can yield more noticeable improvements in daily living and overall well-being ^[3]. Probiotic use has been proposed as a natural as well as synthetic source in the way to improve gut health, boost immunity, and support better mood and mental clarity. These benefits may work together to improve overall well-being and satisfaction with life. Hence, it is essential to implement probiotics supplementation as treatment strategies that accurately improves health and preserve quality of life ^[4,5,6]. Quality of Life is a dynamic and subjective state of well-being that encompasses an individual's overall satisfaction with life, shaped by the harmony between their physical condition, emotional resilience, meaningful relationships, sense of purpose, and the ability to engage with and adapt to their environment in a way that aligns with personal values and aspirations ^[7]. Health-Related Quality of Life (HRQOL) describes how people feel about their overall well-being, considering their cultural background, personal values, life goals, and what matters most to them. This is a comprehensive concept influenced by various factors, including physical health, psychological state, level of independence, social relationships, and interactions with key aspects of their environment ^[8]. Life satisfaction assessment is essential in measuring the effectiveness of healthcare, particularly in older adults. One common tool for this purpose is the WHOQOL-BREF, developed by the World Health Organization. This scale evaluates various aspects of life, such as physical health, mental well-being, social relationships, and the environment. For older populations, it’s a practical and adaptable tool that helps gauge how interventions or treatments impact their overall well-being and satisfaction with life ^[9,10].

Aging

Aging represents a normal, enduring phase of life common to all people. It brings about gradual changes in the body and mind, making individuals more prone to illnesses and reducing their ability to recover quickly. This process is influenced not only by biology but also by one’s genetics, lifestyle, environment, and socioeconomic status. Everyone ages differently, and the effects of aging vary from person to person ^[11,12]. Over the course of aging, various aspects of their health and daily life are affected, as shown in (Figure 1.) These changes occur across several key areas:

Figure 1. Changes during aging

1. Physical and Biological Changes

• Muscles and Bones: Muscle mass and bone density naturally decline, which can lead to reduced strength, flexibility, and balance—making movement more difficult.
• Heart and Blood Vessels: Blood vessels become stiffer, and the heart may not pump as efficiently, raising the risk of high blood pressure and heart disease.
• Lungs: Lung capacity and elasticity decrease, making breathing less effective, especially during physical activity.
• Immune System: The immune response weakens with age, leading to a higher risk of infections and a slower healing process.
• Digestive System: Digestion can become slower, and nutrient absorption may be less efficient. Changes in gut bacteria and stomach acid levels are also common.
• Senses: Vision, hearing, taste, and smell often decline, which can affect communication, appetite, and enjoyment of daily life.
• Skin and Hair: As we age, the skin tends to lose its firmness and becomes more delicate, often resulting in wrinkles and a less youthful appearance. Hair may turn gray or fall out over time ^[13,14].

2. Cognitive and Neurological Changes:

• Memory: Many older adults notice changes in memory, especially short-term memory, and slower information processing.
• Thinking Skills: Tasks that involve planning, decision-making, or handling multiple things at once may become more difficult.
• Brain Health: As people get older, their chances of developing memory-related conditions like Alzheimer’s and other forms of dementia become higher.
• Sleep: Sleep patterns often shift, leading to lighter, more fragmented sleep and earlier waking hours ^[15,16].

3. Psychological and Emotional Changes:

• Mental Well-Being: Older adults may be more prone to depression, anxiety, or loneliness, especially after losing loved ones or facing health issues.
• Emotional Resilience: While some find greater emotional balance with age, adapting to change can become more challenging.
• Sense of Identity: Major life transitions like retirement or changes in physical ability—can affect self-esteem and how individuals see themselves ^[17,18].

4. Social and Environmental Changes:

• Relationships and Roles: Retirement, caregiving duties, or the loss of a spouse or peers can shift social roles and support networks.
• Living Situation: Many older adults live alone or in assisted facilities, which can affect their sense of independence and comfort.
• Finances: A fixed income or financial reliance on others can limit access to healthcare and social opportunities.
• Isolation: Smaller social circles or reduced mobility can lead to loneliness and a decline in mental health ^[19,20].

5. Functional Decline and Quality of Life:

• Basic Daily Tasks (ADLs): Activities like bathing, dressing, or feeding oneself can become more difficult.
• Complex Daily Tasks (IADLs): Managing medications, money, or transportation may require help.
• Overall Well-being: All these changes together can influence a person’s independence, autonomy, and satisfaction with life ^[21,22].

Advancing age affects far more than just the body it shapes every part of a person’s life. Being aware of these shifts is vital for ensuring a positive and enriched aging experience. With the right care, understanding, and resources, older adults can continue to live with dignity, purpose, and a good quality of life ^[23].

Geriatric Population

The geriatric population comprises individuals aged 65 years and above, marked by age-related physiological, functional, and cognitive changes that impact their healthcare needs ^[24,25]. This group is commonly classified into two: age based classification and functional classification as shown in (Figure 2.)

Figure 2. Geriatric population classification based on age and functionality

1. Age-Based Classification

During aging, their experiences, health, and abilities can vary greatly. Here’s a look at the different age groups within the older population and what typically characterizes them:

• Young-Old (65–74 years): Elderly individuals in this group are still healthy and active. They often live independently, remain socially engaged, and may even continue working or volunteering.
• Middle-Old (75–84 years): This stage often brings the onset of chronic health issues like high blood pressure or diabetes. Some may begin to notice changes in physical strength or memory, though many still manage their daily lives with minimal assistance.
• Oldest-Old (85+ years): People in this group tend to be more vulnerable. They are more likely to experience physical weakness, memory challenges, and require support with daily activities. Conditions like dementia and osteoporosis become more common.
• Centenarians (100+ years): Turning 100 is an extraordinary achievement. While some centenarians remain mentally sharp and fairly independent, others may face significant cognitive or physical decline. Their longevity is often associated with a mix of good genes, a healthy lifestyle, and low stress.
• Supercentenarians (110+ years): This group of elderly people are rare who lives more than 110 years. Their longevity stands out as a remarkable example of human lifespan potential. Interestingly, many stay relatively healthy and free from serious illness until quite late in life, defying the usual expectations of aging ^[26,27].

2.  Functional Classification

As people grow older, their ability to live independently and handle everyday tasks can differ greatly from one person to another. This classification helps us understand the different stages of functional ability among older adults:

• Robust Elderly: These individuals remain active and independent, managing their daily routines with little to no difficulty. They may have chronic health conditions, but these are usually well controlled and don’t interfere significantly with daily life or self-care.
• Pre-Frail Elderly: This group is beginning to show early signs of physical or functional decline, such as slower movement or increased tiredness. While they can still manage most tasks, they might occasionally need help with more complex responsibilities like managing medications or finances. Even small health issues could push them toward greater frailty.
• Frail Elderly: These individuals experience noticeable physical weakness and are more vulnerable to health problems. They often struggle with weight loss, fatigue, and slower movement. Their risk of falling, hospitalization, or loss of independence is higher. Many require help with both basic tasks (like bathing or dressing) and more involved ones (like cooking or shopping).
• Dependent Elderly: This group needs regular support for everyday tasks due to serious physical or mental health challenges. They may be unable to care for themselves without help and often rely on caregivers or long-term care facilities. Conditions like advanced dementia, stroke, or severe disability are common, and some may be bedridden or fully dependent on others. ^[28,29].

Impact of Aging On Drug Kinetics

The natural changes in our bodies can have a big impact on how medications work and how our body responds to them. These changes affect every stage from how drugs enter the body to how they’re removed ^[30,31].

Absorption

• Gastric acid production declines, leading to altered drug solubility.
• Delayed gastric emptying and reduced splanchnic blood flow may slightly slow absorption.
• Intestinal surface area may decrease, but overall drug absorption is often not significantly impaired.
• Conditions like achlorhydria and bacterial overgrowth can affect the bioavailability of some drugs (e.g., calcium carbonate, digoxin).

Distribution

• Increased body fat alters the volume of distribution (Vd) for lipophilic drugs (e.g., diazepam), prolonging their half-life.
• Decreased lean body mass and total body water reduce Vd for hydrophilic drugs (e.g., aminoglycosides), possibly increasing plasma concentration.
• Lower serum albumin levels can affect protein binding, increasing free (active) drug levels for highly protein-bound drugs (e.g., phenytoin, warfarin).

Metabolism

• Liver size and hepatic blood flow decrease, especially impacting first-pass metabolism.
• Phase I reactions (oxidation, reduction, hydrolysis), often catalyzed by cytochrome P450 enzymes, may be slowed.
• Phase II reactions (conjugation: glucuronidation, sulfation) are usually preserved.
• Some drugs may have prolonged half-lives and increased plasma levels (e.g., theophylline, propranolol).

Excretion:

• Renal function typically declines with age, even without overt disease.
• Glomerular filtration rate (GFR), renal blood flow, and tubular function are reduced.
• Drugs primarily excreted by the kidneys (e.g., aminoglycosides, digoxin, lithium) may accumulate, increasing the risk of toxicity.
• Creatinine clearance (CrCl) should be estimated (e.g., via Cockcroft-Gault formula) for proper dose adjustments, as serum creatinine alone may not reflect renal function in older adults due to reduced muscle mass ^[30,31].

Impact Of Aging On Drug Response

Pharmacodynamics is the study of how the body reacts to medications and how those drugs produce their effects. During aging, these responses can shift noticeably^[32,33].

• Increased Sensitivity: Older individuals may be more affected by certain drugs, such as blood thinners, pain relievers, or sleep aids. This heightened sensitivity can make them more vulnerable to side effects like excessive drowsiness, difficulty breathing, or an increased risk of bleeding.

• Reduced Effectiveness: Aging reduces the body’s ability to compensate for drug induced changes.  Some drugs, like beta-blockers, may not work as well in the elderly. This is partly due to changes in how the body’s cells respond to these medications.
• Weakened Balance Systems: aged people can make it harder for the body to maintain internal balance, making older individuals more prone to issues like sudden drops in blood pressure with antihypertensives or low blood sugar from diabetes medications ^[32,33].

Role of Probiotics In Improving Quality Of Life In Geriatric Population

Probiotics are viable microorganisms that, when taken adequately enhance the health of the host. They are inherently non-pathogenic and contribute positively to host well-being. Aging-related dysbiosis refers to an imbalance or disturbance in the structure and function of the gut microbiota. This condition is characterized by a reduction in microbial diversity, an excessive proliferation of potentially harmful bacteria, accompanied by a reduction in beneficial microbes. Thus, the probiotics play a vital role in enhancing digestive health, immune function and cognitive function by maintaining a balanced gut microbiota ^[34]. Gut microbial enhancers support digestive health by reinforcing the gut epithelial barrier, strengthening the intestinal lining, stimulating the secretion of mucins and defensins, and preventing harmful substances from leaking into the bloodstream (a condition known as leaky gut). They also enhance adhesion to the intestinal mucosa by binding to the intestinal surface, promoting colonization and stability, and inhibit pathogen attachment to epithelial cells by occupying available binding sites ^[35]. Competitive exclusion of pathogenic microorganisms by outcompete with the harmful microbes for nutrients and space, reducing gastrointestinal symptoms like constipation and diarrhea in conditions like IBD, Clostridium difficile or helicobacter pylori associated infections, gastroenteritis, gastritis and enteric fever. It generates the lactase enzyme, facilitating the digestion of dairy products in individuals with lactose intolerance, while also enhancing nutrient absorption ^[36]. Production of anti-microorganism substances by secreting antimicrobial compounds that inhibit pathogen growth. Immune system modulation occurs through interactions with dendritic cells (DCs) and macrophages in the lamina propria, influencing the production of cytokines (such as IL-10 and TGF-β), which in turn regulate the differentiation of immune cells (Treg, Th1, Th2, Th17), thereby shaping immune responses^.Normal flora balancers strengthen immune function by stimulating the production of immune cells like macrophages, dendritic cells, and natural killer (NK) cells and boosting the body’s ability to fight infections. They also reinforce the intestinal barrier, preventing the entry of harmful pathogens and toxins into the bloodstream. Probiotic strains modulate the production of pro-inflammatory and anti-inflammatory cytokines, helping control chronic inflammation and promoting immune balance ^[37]. Live beneficial microorganisms can increase the levels of immunoglobulin A (IgA) in the mucosa, which is important for neutralizing pathogens at entry points like the gut and respiratory tract. This flora- friendly microbes can assist the immune system in distinguishing between harmful and harmless agents, thereby potentially minimizing allergic reactions and autoimmune responses. Probiotic supplementation also enhance the efficacy of vaccines by improving the body's immune response to the antigens ^[38]. Functional microbes improve cognitive function by influencing the gut-brain axis, the bidirectional communication network between the gut and the brain by enhancing the gut barrier and blood-brain barrier integrity by preventing harmful substances from reaching the brain and affecting neurological function. It can produce or influence neurotransmitters like serotonin, dopamine, and GABA, which regulate mood, memory, and cognition and immune responses through inflammatory cytokines and immune cells ^[39]. Within the gut lumen, short-chain fatty acids (SCFAs) and neurotransmitters are also produced by the intestinal epithelium, contributing to this complex interaction. It can also can modulate the HPA (hypothalamic-pituitary-adrenal) axis, reducing stress hormone (cortisol) levels and improving resilience to stress^[40].

Figure 3. Demonstration of interconnected benefits of probiotics

Together, these effects demonstrate the interconnected benefits of probiotics (Figure 3.)  across multiple systems. This results in improved quality of life and better overall health particularly beneficial in elderly individuals ^[41,42].

Assessment of Quality Of Life In Geriatric Population Using Whoqol- Bref Scale

Quality Of Life And Health Related Quality Of Life

Quality of Life (QoL) pertains to holistic wellbeing, spanning bodily health, emotional balance and social engagement. Health-Related Quality of Life (HRQoL) specifically focuses on how health status that is both physical and mental aspect impacts on a person’s ability to live a fulfilling life. It is a key indicator used to assess the effectiveness of healthcare interventions and the overall burden of disease ^[43,44].

Need Of Improvement Of Quality Of Life In Geriatric Population When Compared To Other Populations

The geriatric population generally includes individuals who are 65 years of age or older. The geriatric population is widely recognized as one of the most vulnerable groups when it comes to quality of life. Aging is often accompanied by multiple chronic health conditions, reduced physiological reserve, cognitive decline, and functional impairments, all of which can negatively impact daily living and independence. In addition, older adults are more susceptible to psychosocial challenges such as social isolation, bereavement, depression, and reduced economic stability following retirement ^[45]. They faces unique challenges that significantly impact their quality of life more than other age groups. The geriatric population experiences a range of age-related physiological, psychological, and social changes that significantly affect their quality of life, more so than other age groups ^[46]. With advancing age, the prevalence of chronic illnesses such as hypertension, diabetes, arthritis, and cognitive impairments like dementia increases. These health challenges often lead to reduced mobility, dependency, and frequent hospital visits. Unlike younger populations who typically enjoy better physical health and social integration, elderly individuals often face functional decline and a loss of independence. This makes it imperative to focus on improving their overall well-being through appropriate medical care, rehabilitation, and social support systems ^[47]. Enhancing the quality of life in older adults is essential because:

• Increased Life Expectancy: With global aging, a longer lifespan does not necessarily equate to a healthier life unless accompanied by improved well-being.
• Higher Disease Burden: Older adults are more susceptible to chronic diseases like arthritis, diabetes, cardiovascular conditions, and neurodegenerative disorders.
• Psychosocial Challenges: Loneliness, depression, and cognitive impairments like dementia are more prevalent, affecting mental health and life satisfaction.
• Economic and Care Burden: Without improved quality of life, the economic burden on families and healthcare systems increases due to frequent hospitalizations and long-term care.
• Right to Dignity: Growing older with dignity and independence is a fundamental human right, highlighting the importance of personalized healthcare, social inclusion, and supportive environments ^[48].

The people in later adult hood often face a compression of support, a shrinking social circle due to the loss of peers and changing family dynamics making them more susceptible to neglect, depression, and dependency. In contrast, other age groups typically benefit from stronger social networks and better health reserves. Improving the quality of life in geriatric individuals thus requires a multidimensional strategy that is integrating palliative care, geriatric mental health, accessibility improvements, age-friendly environments, and policies that prioritize aging in place with dignity and purpose ^[49] In addition to physical health concerns, the elderly frequently encounters mental health issues such as depression, anxiety, and loneliness, often exacerbated by the loss of a spouse or reduced family interaction. These psychosocial factors further deteriorate their quality of life and may go unnoticed or untreated ^[50]. Enhancing quality of life in the elderly, therefore, requires a holistic approach that addresses not only medical needs but also emotional and social well-being. Compared to other populations, the geriatric group has unique needs that demand specialized care models, community-based support, and policy-level interventions to promote healthy and dignified aging ^[51]. These combined physical, mental, and social factors increase the risk of diminished well-being and life satisfaction in later years. Moreover, the geriatric population often faces barriers to accessing healthcare, nutritional support, and social services, making them more reliant on public health interventions and caregiving systems. Given their increased needs and limited adaptability, improving the quality of life in elderly individuals is a public health priority that requires a multidimensional, patient-centered approach ^[52].

WHO QOL- BREF SCALE

The WHO developed WHOQOL-BREF is a globally recognized tool developed by the World Health Organization to explore how individuals feel about different aspects of their lives. It's designed to be used across various cultures and health conditions, offering a broad and inclusive understanding of a person's overall well-being from physical and emotional health to social relationships and daily environment ^[53]. It is a shortened version of the original WHOQOL-100 and consists of 26 items, covering four key domains as shown in the (table 1.) that is physical health, physiological health, social relationships and environmental quality of life. Additionally, the WHO-BREF includes two global questions that is one assessing the individual’s general perception of quality of life and the other evaluating overall well-being and health ^[54]. The quality of assessment tool is culturally sensitive and has been validated in multiple languages, making it suitable for global use in both clinical and research settings. The WHOQOL-BREF is designed to capture the individual's subjective perspective on their life, rather than relying solely on objective health indicators ^[55].

Table 1. Domains of WHOQOL BREF Scale

It provides a holistic view of well-being by encompassing not only physical health but also emotional status, social support, and environmental factors such as financial security and access to healthcare. The questionnaire is meant to be filled out by individuals themselves and typically takes less than 10 minutes to complete. Its psychometric strength, ease of use, and global adaptability make it a valuable tool in assessing quality of life among diverse populations, including patients with chronic illness, the elderly, and the general public ^[56].

• The physical domain (7 items) assesses aspects such as physical functioning (energy levels, fatigue, mobility, sleep and rest, activities of daily living, work capacity) and pain and discomfort.
• The physiological health domain (6 items) assesses aspects such as mental well-being (including positive and negative emotions), spirituality, religious beliefs, personal values, cognitive functions (such as thinking, learning, memory, and concentration), body image, physical appearance, and self-esteem.
• The social relationships domain (3 items) measures personal relationships, sexual activity, social support, and an individual’s ability to engage in social activities.
• The environmental health domain (8 items) focuses on the surrounding environment, considering factors like freedom, physical safety, security, physical environment (pollution/ noise/ traffic/ climate), financial resources, opportunities for acquiring new information and skills, participation in and  opportunities for recreation, home environment, health and social care; accessibility and quality and transport.
• Furthermore, two general questions evaluate overall quality of life and general health satisfaction ^[57,58].

All these domains work together to shape a person’s overall sense of well-being and daily functioning, with positive changes in any area contributing to a more fulfilling and comfortable life^[58]. This scale provides a clear way to assess quality of life by considering physical health, mental state, social relationships, and the living environment. Focusing on these key areas allows for a fuller understanding of an individual's well-being, highlighting the importance of improving all aspects of life ^[59]. The scoring and interpretation is based on the measure of response on a 5-point scale ranging from 1-5, with higher scores indicating better quality of life. The scores for each domain’s score is determined by computing the average of the responses to the items it contains. It generates a composite score reflecting each of the four dimensions. Except pain and discomfort (3), dependence on medical substances and medical aids (4) and negative feelings (26) sub domains are reverse or back scored and other sub domains are orginal scoring domains ^[60]. Each item is scored on a 5-point Likert scale (1 = very poor/dissatisfied to 5 = very good/satisfied). To get the score for each area, the individual responses within that section are added together. The raw scores are standardized on a scale from 0-100, where higher scores indicating a more favourable quality of life ^[61]. The (Table 2.)  shows the formula for calculating each domain:

Table 2. Each domains score calculating formula