Current Landscape and Overview of Gastrointestinal Health in Indonesian Children: A Scoping Review

3.1. Theme 1: Epidemiology of Gastrointestinal Health in Indonesia

The state of gastrointestinal (GI) health is in constant flux, shaped by the ongoing interplay between diet, gut microbiome, hygiene practices, and socioeconomic factors. As the most populous developing nation, Indonesia grapples with a rising incidence of both infectious and non-infectious GI ailments. A 2017 national survey revealed that diarrhea, gastroenteritis, and colitis ranked fifth among the most prevalent reasons for outpatient visits in Indonesia. Diarrhea alone affected over 1 million patients, with 90,000 cases involving children under five years old [11, 15]. Common pathogens included Rotavirus, E. coli, Shigella spp, and Entamoeba histolytica, mirroring findings from a comparable study on Ghanaian children [16, 17].

In recent years, Indonesia has witnessed an uptick in non-infectious GI disorders, particularly functional gastrointestinal disorders (FGIDs). A 2019 cross-sectional study in Jakarta, analyzing 1800 questionnaires, found that 11.5% of respondents reported FGIDs. These included functional abdominal pain (5.8%), functional dyspepsia (3.3%), irritable bowel syndrome (2%), and abdominal migraine (0.4%) [18]. Dyspepsia was another frequent cause of outpatient visits, with a study on 550 dyspepsia patients revealing gastritis in 44.7% and duodenitis in 6.5% of cases [14]. It is worth noting that comprehensive epidemiological data on pediatric GI diseases in Indonesia, especially for children under 5, remains scarce, with most studies focusing on adolescent populations.

Beyond specific GI disorders, a child's digestive health can be further compromised by factors, such as malnutrition and socioeconomic disadvantage. Indonesian children under 5 often face dietary challenges, including infrequent consumption of animal proteins, fruits, and vegetables, as well as micronutrient deficiencies [19]. Families in rural areas or with lower educational attainment are more likely to have malnourished children compared to their urban or more educated counterparts [15]. A summary of the relevant studies is presented in Tables 1 and 2.

3.2. Theme 2: Infectious GI Diseases and Non-infectious GI Diseases

Bacterial and helminth-induced gastrointestinal infections remain a significant global health concern, with younger individuals at heightened risk [20, 21]. In developing nations like Indonesia, these issues are particularly acute. A 2014 study by Tan et al. estimated that about 200 million people across 31 provinces were at risk of Soil-Transmitted-Helminth (STH) infections [22]. A 2020 epidemiological study in Semarang, Central Java, found that nearly one-third of 6,466 participants from 2,195 households had active STH infections [23]. While affecting both children and adults, childhood STH infections are more devastating, potentially leading to nutritional, physical, and cognitive impairments that perpetuate poverty cycles [23, 24]. School-age children face the highest risk of STH infections and their long-term consequences [23].

Pediatric gastrointestinal infections in Indonesia vary by age group. Bacterial pathogens like Salmonella spp. (causing typhoid fever) and Shigella spp. (causing dysentery) are common, especially in children aged 2-4 years. Escherichia coli, particularly enterotoxigenic and enteropathogenic types, frequently cause diarrhea in infants and young children, exacerbated by malnutrition and poor sanitation.

Viral infections, notably Norovirus and Rotavirus, are significant contributors to gastroenteritis in children and adults. A study by Nirmawati et al. found that out of 406 patients, 18.47% tested positive for Norovirus and 54.93% for Rotavirus. These infections, causing dehydration, diarrhea, vomiting, and fever, can disrupt children's nutritional absorption. While affecting children aged 0-60 months, Rotavirus infections clustered in the 7-24 month age group, and Norovirus in the 7-36 month group.

Rotavirus remains the leading cause of severe diarrhea globally, particularly affecting Indonesian infants and young children aged 6-24 months. Norovirus peaks in prevalence among children aged 7-36 months, as reflected in acute gastroenteritis hospitalization rates. Both viruses can cause severe dehydration, complicating clinical management.

Recent research has focused on gut dysbiosis, where antibiotic use and gastrointestinal infections alter the gut microbiome. This disturbance in the complex genetic, environmental, and microbial interactions may lead to chronic gastrointestinal pathologies like inflammatory bowel disease and colitis [24, 25]. While data from Indonesia is limited, studies suggest that certain gastrointestinal infections, such as Salmonella Typhi-murium, can induce chronic intestinal inflammation, disrupting the protective barrier function of the human gastrointestinal tract [26].

Non-infectious gastrointestinal conditions like gastro- esophageal reflux disease (GERD), constipation, and functional gastrointestinal disorders (FGIDs) significantly impact children under 5. Their immature GI function, including low levels of lipase, bile salts, and amylase during the first 6 months, predisposes them to these conditions [27]. Infants are particularly susceptible to regurgitation, constipation, and colic, which may lead to FGID symptoms later in life [28, 29]. A 2015 estimate suggested prevalence rates of 20% for infantile colic, 15% for functional constipation, and 30% for regurgitation [29]. Interestingly, a survey of Indonesian general practitioners revealed a weak understanding of functional constipation symptoms, proper toilet training education, and appropriate management [30].

Growing evidence suggests a correlation between gut microbiota alterations and FGI development. Gut hypomotility and dysbiosis can lead to GI dysmotility. Studies have reported that germ-free mice given fecal matter from IBS-D patients exhibited intestinal barrier impairment, immune gut dysfunction, and altered gut microbiota [31-34]. Gut microbe-produced molecules like short-chain fatty acids, serotonin, and tryptamine modulate GI physiology, and patients with gut dysbiosis often display FGID symptoms, including delayed gut transit and smooth muscle contraction/relaxation problems [32-36].

Probiotic use shows potential in FGID treatment and prevention. Infant supplementation with lactobacilli, particularly Lactobacillus reuteri, in the first weeks after birth significantly reduced regurgitation and colic-related crying while increasing daily stool passage [28]. These findings highlight the importance of nutrition in modulating gastrointestinal function and offer promising avenues for managing and preventing functional GI disorders in the future.

3.3. Theme 3: Updates on GI Treatment and Diagnostics

Indonesia's population has been faced with an uptick in both infectious and non-infectious gastrointestinal ailments in recent years. Diarrhea affects over 17% of children under five, highlighting a significant health concern [37]. This rising incidence necessitates improved diagnostic and treatment capabilities. Currently, diarrhea diagnosis primarily relies on patient history and physical assessment, supplemented by additional tests, such as colonoscopy, endoscopy, blood analysis, stool examination, and microscopy, to confirm the diagnosis in pediatric cases [14, 38].

The field of gastroenterology in Indonesia has expanded to incorporate various diagnostic approaches. These include scoring systems like Rome IV and GERD-Q, non-invasive techniques, such as stool tests, PET CT scans, and H. pylori antigen detection, as well as invasive procedures, including endoscopy, magnetic resonance cholangiopancreatography, and ultrasonography. Notably, endoscopic services are now available in more than 313 hospitals nationwide [37, 39].

Despite these advancements, there is a notable lack of research examining the availability and accuracy of these diagnostic methods in Indonesia's rural regions. This gap in knowledge presents an important area for future investigation to ensure equitable access to accurate gastrointestinal diagnostics across the country.

3.4. Theme 4: Interventions

Indonesia has implemented various strategies to manage diarrhea, including the LINTAS Diare program (Lima Langkah Tuntaskan Diare). This five-step approach aims to treat diarrhea, enhance household knowledge, and provide patient monitoring. The initial step involves oral rehydration therapy, with dosage based on symptom severity. Next, zinc supplementation is recommended to reduce condition severity by promoting gastrointestinal wall re-epithelialization. Maintaining food intake and/or breastfeeding is crucial to prevent further nutrient and weight loss. Antibiotics may be prescribed if infection is indicated, though improper use can lead to dysbiosis. Finally, patients or caregivers receive education on home treatment and when to seek hospital care [40].

Numerous studies have recognized diet as a crucial factor influencing gastrointestinal composition and function [41, 42]. Beyond gut health, adequate nutrition plays a vital role in children's physical growth and neurodevelopment [43-45]. In Indonesia, a lack of diverse macro- and micronutrients from monotonous diets significantly contributes to poor child growth, emphasizing the importance of dietary variety [46,47]. Studies by Sari et al. and Torlesse et al. found that households with grain-heavy diets lacking adequate animal protein and vegetables had an increased odds ratio of 1.21 for stunting [45, 46]. A 2021 study by Damayanti et al. further highlighted persistent poor dietary habits among many Indonesian children [47].

Recent research has focused on the interaction between specific food sources and overall GI function, though such findings are less documented in Indonesia. Growing evidence suggests that early adequate nutrition is crucial for establishing a healthy gut microbiota, supporting optimal GI function. Ley et al. demonstrated that breastfed infants have higher proportions of beneficial lactobacilli and bifidobacteria, as well as increased sIgA in stools (a marker of good gut health), compared to formula-fed infants [48]. The timely introduction of solid foods during weaning is well-documented as a primary driver of gut microbiota maturation [41, 18].

Fiber intake is known to offer numerous health benefits, including reduced risk of weight gain, cardiovascular disease, and elevated cholesterol while improving gut health and digestive function [49,50]. High-fiber snacks for children can decrease the risk of painful constipation, promote healthy gut microbiota, and are often associated with better overall diet quality due to their sources (vegetables, fruits, whole grains) [50, 51]. However, fiber intake in Indonesia remains low. A study by Prafianti et al. in the Asmat district of Papua found that over 90% of children consumed fiber below the recommended dietary allowance (1.63 g/day) [52].

Recent research has identified a correlation between gut microbiota composition and child growth. The genus Prevotella 9 appears more abundant in normal-weight children and significantly lower in stunted children. Its levels correlate with dietary fiber intake, suggesting that alterations in gut microbiota may affect nutrient absorption in children [53].

3.5. Theme 5: Short and Long-term Impact

Imbalances in gut microbiota, known as dysbiosis, can have both short-term and enduring impacts on children's health. Research has demonstrated that changes in gut microbiota can significantly influence the immune system. The host's innate immunity is affected by both healthy and dysbiotic gut microbiota through various microbial components and their metabolic products. Dysbiosis may interfere with the host's capacity to identify microbial signatures, potentially altering immune responses. Bacterial interactions also affect other receptors, such as TLR2. A prime example is the oral anaerobe Porp- hyromonas gingivalis, which intensifies inflammation by altering the oral microbiota. This bacterium modifies host immune responses by encouraging MYD88 breakdown, thereby suppressing immunity while sustaining inflam- mation through the interplay between TLR2 and the C5aR complement receptor [54, 55].

The relationship between gut microbiota and cognitive development has also been observed. Studies suggest that gut microbiota plays a crucial role in early-life brain development, leading to lasting behavioral effects. Research has shown that specific bacterial compositions at one year of age can predict cognitive abilities at age two. For instance, clusters with high Faecalibacterium levels (C1) were associated with lower cognitive performance (72^nd percentile), while those with high Bacteroides levels (C2) correlated with higher performance (90^th percentile). Interestingly, greater alpha diversity at age one predicted poorer cognitive outcomes at age two, as measured by ELC, visual reception, and expressive language scales. This finding contradicts the usual understanding that low alpha diversity in infancy typically links to negative health outcomes, such as type 1 diabetes and asthma, while high diversity is often seen as indicative of a more mature, adult-like microbiome [56].

Globally, malnutrition in its various forms continues to be a significant health concern for children. Stunting affects over 150 million children under five, while obesity impacts 40 million [57]. In Indonesia, a complex nutritional landscape exists, characterized by the simultaneous presence of undernutrition and over- nutrition. Some researchers, including Rah (2021), have identified a “triple burden” of malnutrition, which encompasses micronutrient deficiencies. This is evidenced by the prevalence of anemia in one out of every four adolescent girls [58]. While multiple factors contribute to these nutritional issues, including dietary habits, genetic predisposition, and socioeconomic conditions, the composition of a child's gut microbiome has emerged as a critical influencing factor [59, 60].

The interplay between gastrointestinal (GI) diseases, nutritional deficiencies, and intestinal microbial communities forms a complex, self-perpetuating cycle. Dietary choices significantly shape the microbial landscape in children's digestive systems. Research indicates that infants nourished through breastfeeding exhibit elevated populations of B. longum subsp. infantis and Lactobacillus acidophilus when compared to their formula-fed counterparts [59]. Iddrisu et al. observed that alterations in gut microbiota composition, specifically an increase in proteobacteria coupled with a decline in bifidobacterium and lactobacillus, correlate with a higher incidence of diarrheal episodes. These frequent bouts of diarrhea often contribute to malnutrition. Moreover, persistent diarrhea can impair the GI tract's ability to absorb essential nutrients, potentially leading to both physical and cognitive developmental issues [57, 60]. Further insights from the study by Smith et al. revealed that children suffering from kwashiorkor or similar malnutrition disorders typically possess an under- developed gut microbiome. This immature microbial ecosystem is characterized by a predominance of Proteobacteria, Bacteroidetes, and anaerobic Firmicutes, along with reduced overall diversity. These findings underscore the pivotal role that gut microbiota plays in the emergence and progression of malnutrition [61, 62].

Obesity and imbalances in gut microbiota can contribute to the development of obesity. The microbial communities in our digestive system play a crucial role in regulating organ permeability and the body's ability to absorb nutrients. Research by Patterson and colleagues revealed that alterations in the microbiome can lead to enhanced energy extraction and increased fat production. When these processes become excessive, they may trigger tissue inflammation and reduce insulin sensitivity, potentially culminating in obesity [63, 64]. Jumpertz et al. highlighted the distinct differences in microbial populations between individuals with and without obesity. Their findings showed that obese subjects tended to have a higher ratio of Firmicutes to Bacteroides, while the opposite was observed in healthy individuals. Corroborating studies have also noted a greater prevalence of potentially harmful microbes and those involved in short-chain fatty acid synthesis, specifically Actinobacteria and Proteobacteria, in individuals with obesity [65, 66]. These observations highlight the intricate interplay between gut microorganisms and nutritional status in pediatric populations. Notably, children under the age of five who experience either malnutrition or obesity often exhibit reduced physical growth (as measured by weight and height) and demonstrate impaired cognitive abilities when compared to their healthy peers. This underscores the far-reaching impacts of nutritional imbalances and altered gut microbial compositions on overall child development.

3.6. Technological Applications in GI Health Management

Recent advancements in healthcare technology offer promising applications for improving GI health management in Indonesian children. Artificial Intelligence (AI) and Machine Learning (ML) techniques show particular promise in this field. For instance, lightweight Convolutional Neural Network (CNN) models could be adapted for early prediction of GI diseases based on symptoms and risk factors, potentially enabling earlier interventions [67]. ML algorithms have also demonstrated the potential to enhance the accuracy of diagnosing complex GI conditions, which could be particularly valuable in resource-limited settings [68]. In the realm of data management, blockchain technology presents an opportunity to improve the security and accessibility of children's health records, ensuring continuity of care for chronic GI conditions [69]. This could be especially beneficial in a geographically diverse country like Indonesia. The integration of Internet of Things (IoT) devices with edge computing offers possibilities for real-time monitoring of severe GI conditions or tracking nutritional status in remote areas [70]. This technology could help bridge the gap in healthcare access between urban and rural regions of Indonesia. Advanced imaging techniques, such as multi-modality image fusion, could improve the diagnosis of complex GI disorders in pediatric patients [71]. Lastly, the implementation of decision support systems, such as those based on the Analytic Hierarchy Process (AHP), could assist healthcare providers in making informed decisions about GI health management strategies [72]. While these technologies show promise, their implementation in the context of GI health management for Indonesian children requires careful consideration of infrastructure limitations, cost-effectiveness, and cultural appropriateness. Future research should focus on adapting these technologies to the specific needs and constraints of the Indonesian healthcare system.