Association Between Digestive Health, Lifestyle Factors And Skin Health Among Young Adults: A Cross-Sectional Study Of The Gut–Skin Axis

The human body functions as an intricately interconnected system wherein various organs communicate through complex signaling networks to maintain physiological homeostasis and overall health. Among these inter-organ interactions, the relationship between the gastrointestinal tract and the skin has garnered substantial scientific interest in recent years. This connection, termed the gut–skin axis, represents a bidirectional communication pathway linking the gut and skin through immune, metabolic, hormonal, and inflammatory signaling cascades.¹

The gastrointestinal tract harbors trillions of microorganisms collectively known as the gut microbiota, which play an indispensable role in digestion, nutrient absorption, immune regulation, maintenance of intestinal barrier integrity, and protection against pathogenic colonization.² The composition and functional capacity of the gut microbiome are influenced by numerous factors including dietary habits, host genetics, medication use, stress, and environmental exposures.³ Disruption in the balance of these microbial communities, termed gut dysbiosis, has been implicated in various pathological conditions affecting both gastrointestinal function and distal organ systems, including the skin.

The gut microbiota contributes to host health through multiple mechanisms, including the fermentation of indigestible dietary components to produce short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which serve as energy sources for colonocytes and modulate immune responses.⁴ Additionally, gut microbes regulate intestinal barrier function, compete with pathogens for ecological niches, synthesize essential vitamins, and metabolize xenobiotics. However, factors including Western dietary patterns characterized by high fat and refined sugar content, chronic psychological stress, insufficient sleep duration, physical inactivity, and medication use—particularly antibiotics—may disturb microbial homeostasis, compromising intestinal barrier integrity and promoting systemic low-grade inflammation.⁵

Skin health is influenced by a complex interplay of genetic predisposition, hormonal regulation, nutritional status, environmental exposures, and lifestyle practices. Emerging evidence indicates that internal factors, particularly gut health and microbial composition, may significantly contribute to skin conditions through immune and inflammatory mechanisms. Dysbiosis of the gut microbiota has been associated with various dermatological conditions including acne vulgaris, atopic dermatitis, psoriasis, and rosacea, potentially through promotion of systemic inflammation and modulation of immune responses.⁶˒⁷ The gut–skin axis operates through multiple pathways including the immune system, neuroendocrine system, and metabolic regulation, creating a complex network of interactions that influence skin homeostasis and pathology.⁸

Lifestyle factors including dietary patterns, physical activity levels, sleep quality, hydration status, and psychological stress play pivotal roles in maintaining both gut and skin health. Diets rich in fruits, vegetables, whole grains, and dietary fiber increase the growth of beneficial gut microorganisms, whereas frequent consumption of processed foods, refined sugars, and saturated fats may adversely affect microbial diversity and metabolic function.⁵ Similarly, chronic sleep deprivation and psychological stress can compromise intestinal barrier function, increase pro-inflammatory cytokine production, and exacerbate dermatological conditions through activation of the hypothalamic–pituitary–adrenal (HPA) axis.⁹ Regular physical activity has been associated with enhanced gut microbial diversity, reduced inflammatory markers, and improved overall health outcomes.¹⁰

Young adulthood represents a critical developmental period during which lifestyle behaviors are often significantly influenced by academic demands, occupational responsibilities, and social factors. Irregular meal patterns, increased consumption of energy-dense nutrient-poor foods, inadequate sleep, and elevated stress levels are commonly observed among young adults and may negatively impact both digestive and skin health. While previous investigations have explored the relationship between gut microbiota and specific dermatological disorders, limited research has comprehensively examined the combined influence of digestive health, lifestyle factors, and overall skin health among healthy young adult populations.¹¹˒¹²

Therefore, the present study was undertaken to explore the relationship between digestive health, lifestyle factors, and skin health among young adults aged 18–26 years. The findings of this investigation may contribute to increasing awareness regarding the importance of maintaining digestive balance and adopting healthy lifestyle practices for promoting optimal skin health, potentially informing future public health interventions and educational programs targeting this demographic.

MATERIALS AND METHODS

Study Design and Population:

The present study employed a cross-sectional research design to investigate the relationship between digestive health, lifestyle factors, and skin health among young adults. The study was conducted among 100 participants aged 18–26 years, selected using a convenience sampling method from the student population of Veeranari Chakali Ilamma Women's University, Hyderabad, India. Individuals who met the inclusion criteria and provided written informed consent were enrolled in the study.

Inclusion Criteria:

· Age between 18 and 26 years

· Willingness to participate and provide informed consent

· Ability to comprehend and respond to the questionnaire

· Currently enrolled as a student at the university

Exclusion Criteria:

· Individuals with diagnosed chronic gastrointestinal disorders (e.g., inflammatory bowel disease, celiac disease, irritable bowel syndrome)

· Individuals with diagnosed chronic skin conditions requiring ongoing medical treatment (e.g., severe psoriasis, eczema)

· Pregnant or lactating women

Data Collection Tool:

Data were collected using a structured questionnaire specifically developed for the study after review of relevant literature. The questionnaire comprised five sections: socio-demographic characteristics, anthropometric assessment, digestive health indicators, lifestyle factors, and skin health parameters. The questionnaire was administered online through Google Forms, and responses were collected following receipt of informed consent from all participants.

Questionnaire Validation

The questionnaire was prepared after reviewing relevant published literature on digestive health, lifestyle factors, and skin health. Before the main study, it was pilot-tested among 10 participants to evaluate the clarity, sequence, and understanding of the questions. Based on their feedback, minor changes were made to improve the wording and overall clarity of the questionnaire. The revised questionnaire was then used to collect data from the final sample of 100 participants. The responses from the pilot study were not included in the final analysis.

Assessment of Digestive Health:

Digestive health was assessed using questions pertaining to bowel habits (frequency and consistency), bloating, gastric acidity, abdominal discomfort, constipation, diarrhea, and other commonly reported gastrointestinal symptoms experienced over the preceding three months. Each symptom was scored on a Likert scale (1 = never, 2 = rarely, 3 = sometimes, 4 = often, 5 = always). Total scores were calculated and categorized as follows: good (score ≤ 15), average (score 16–25), or poor (score ≥ 26) based on composite scores and distribution tertiles.

Assessment of Lifestyle Factors:

Lifestyle factors were evaluated using questions on dietary habits (frequency of consumption of fruits, vegetables, whole grains, processed foods, sugary foods, fiber-rich foods, and fermented foods), daily water intake (<2 L, 2-3 L, >3 L), physical activity levels (sedentary, moderate, vigorous based on weekly frequency and duration), sleep duration (<6 hours, 6-8 hours, >8 hours), perceived stress levels (low, moderate, high), and meal-skipping behavior (never, sometimes, often). Responses were scored and categorized to evaluate the overall lifestyle pattern of participants, classified as good, average, or poor based on composite scores.

Assessment of Skin Health:

Skin health was assessed using self-reported information on common skin concerns, including acne (frequency and severity), dryness, pigmentation, skin sensitivity, and overall skin condition over the preceding three months. Participants rated the severity and frequency of these concerns on a Likert scale. Responses were analyzed to assess skin health status, categorized as good, average, or poor based on composite scores and distribution tertiles.

Anthropometric Assessment:

Body Mass Index (BMI) was calculated using self-reported height and weight measurements using the formula: BMI = weight (kg) / height (m²). Participants were classified according to the World Health Organization (WHO) BMI classification: underweight (<18.5 kg/m²), normal weight (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥30.0 kg/m²).

Statistical Analysis:

The collected data were entered into Microsoft Excel and analyzed using JASP software (Version 0.16.4). Descriptive statistics were used to summarize the socio-demographic characteristics, anthropometric measurements, digestive health, lifestyle factors, and skin health of the participants. Categorical variables were expressed as frequencies and percentages. The Chi-square test of independence was performed to assess the association between lifestyle factors and skin health, lifestyle factors and digestive health, and digestive health and skin health. The Chi-square statistic (χ²), degrees of freedom (df), and corresponding p-values were reported for each analysis. A p-value of less than 0.05 was considered statistically significant.

Ethical Considerations:

The study was conducted in accordance with the ethical principles of the Declaration of Helsinki. Participation in the study was entirely voluntary. All participants were informed about the purpose, objectives, and procedures of the study before data collection, and informed consent was obtained from each participant. Participants were assured that their responses would remain confidential and anonymous, and that the information collected would be used solely for research purposes. They were also informed that they were free to withdraw from the study at any stage without providing a reason and without any consequences.

RESULTS

Table 1: Socio-demographic characteristics

Interpretation: Table 1 presents the socio-demographic characteristics of the study participants. A total of 100 young adults were included in the study, with the majority belonging to the 21–23 years age group (n = 54, 54%), followed by the 18–20 years group (n = 29, 29%) and the 24–26 years group (n = 17, 17%). The study population was predominantly female (n = 93, 93%), reflecting the institutional demographic of the women's university. Regarding educational status, the majority were postgraduate students (n = 53, 53%), followed by undergraduate students (n = 43, 43%), with a small proportion falling into the "others" category (n = 4, 4%).

Table 2: Distribution of participants based on Body Mass Index (BMI)

Interpretation: Table 2 depicts the distribution of participants according to BMI classification. The majority of participants had normal BMI (n = 50, 50%), followed by overweight (n = 27, 27%) and underweight (n = 23, 23%). No participants were classified as obese.

Table 3: Association between Lifestyle factors and skin health

Chi-square Test: χ² = 10.88, df = 4, p-value = 0.027

Interpretation: Table 3 presents the association between lifestyle factors and skin health among the study participants. It was observed that participants with good lifestyle practices tend to have a good skin health, whereas those with poor lifestyle practices were more likely to have average or poor skin health. Participants with average lifestyle practices showed a mixed distribution across all categories of skin health. The Chi-square value was 10.88 with 4 degrees of freedom, and the p-value was 0.027, indicating a statistically significant association between lifestyle factors and skin health. These findings suggest that maintaining healthy lifestyle practices may contribute to better skin health among young adults.

Table 4: Association between Lifestyle factors and Gut health

Chi-square Test: χ² = 11.85, df = 2, p-value = 0.002

Interpretation: Table 4 shows the association between lifestyle factors and gut health among the study participants. Participants with healthier lifestyle practices demonstrated better gut health, while those with poorer lifestyle practices were more likely to have average gut health. No participants were classified under the poor gut health category based on the predefined scoring criteria; therefore, this category contained no observations in the final analysis. Overall, the findings indicate a positive relationship between healthy lifestyle behaviours and digestive health. The Chi-square value was 11.85 with 2 degrees of freedom, and the p-value was 0.002, indicating a statistically significant association between lifestyle factors and gut health. These findings suggest that healthy lifestyle habits play an important role in maintaining good digestive health among young adults.

Table 5: Association between Gut health and Skin health