Childhood gastroenteritis establishes gastrointestinal disease and increase the economic burden, and the pediatric population is especially vulnerable to these gastrointestinal infections. The aim of this study is to evaluate the role of intestinal microbiota and their relationship with childhood gastroenteritis.

Childhood gastroenteritis establishes gastrointestinal disease and increase the economic burden, and the pediatric population is especially vulnerable to these gastrointestinal infections. According to a World Health Organization report in 2003, the median incidence of diarrhea for all children age under 5 years was 3.2 episodes per child-year, and this number has not changed significantly since 1980s. In Taiwan, the enteric pathogens associated mortality is low, but the social burden and economic costs are substantial because of the high incidence.

Intestinal microflora are able to use the substances consumed in the diet: bacteria can transform complex polysaccharides and monosaccharides in short-chain fatty acids. Short-chain fatty acids are a source of energy for colonocytes and directly affect the storage of lipids and the absorption and metabolism of food, creating the so-called 'second meal effect'.

Qualitative and quantitative alterations of commensal flora may result in various gastrointestinal and extraintestinal diseases. One of the first interactions these bacteria have when interacting with the intestinal epithelial cells lining the GI tact.

The first aim of this study is to evaluate the role of intestinal microbiota and their relationship with childhood gastroenteritis. The second aim of this study is determining the inflammatory markers (such as fecal TNF-α, interleukin -6, calprotectin, lactoferrin) on the host of childhood gastroenteritis. The investigators try to seek to gain an advanced understanding effect of intestinal microbiota and fecal inflammatory marker in the childhood gastroenteritis.

Inclusion Criteria:

• Children with or without diarrhea less than three days

Exclusion Criteria:

• diabetes
• chronic liver disease

Children with or without diarrhea less than three days, or healthy volunteers. The age of participants is from 6-month-old to 12-year-old.