Table 1. Enriched KEGG pathways (level 1, 2 and 3) according to the digestive tract microbiota of the digestive tract of white shrimp (Litopenaeus vannamei) with significant differences (p < 0.05) based on the Kruskal–Wallis test.

Fraction	KEGG Level-1 and Level-2	KEGG Level-3
Foregut	Metabolism; Amino acid metabolism	Glycine, serine and threonine metabolism
	Metabolism; Amino acid metabolism	Valine, leucine and isoleucine biosynthesis
	Metabolism; Amino acid metabolism	Arginine and proline metabolism
	Metabolism; Amino acid metabolism	Lysine degradation
	Metabolism; Carbohydrate metabolism	C5-Branched dibasic acid metabolism
	Metabolism; Carbohydrate metabolism	Glyoxylate and dicarboxylate metabolism
	Metabolism; Energy metabolism	Carbon fixation pathways in prokaryotes
	Metabolism; Metabolism of other amino acids	D-Arginine and D-ornithine metabolism
	Metabolism; Xenobiotics biodegradation and metabolism	Chloroalkane and chloroalkene degradation
	Metabolism; Xenobiotics biodegradation and metabolism	Polycyclic aromatic hydrocarbon degradation
	Cellular processes; Cell growth and death	Apostosis
	Ribosome biogenesis in eukaryotes; Translation	Ribosome biogenesis in eukaryotes
Midgut	Genetic information processing; Folding, sorting and degradation	Protein processing in endoplasmic reticulum
	Genetic Information Processing; Folding, sorting and degradation	Sulfur relay system
	Metabolism; Amino acid metabolism	Tryptophan metabolism
	Metabolism; Lipid metabolism	Glycerophospholipid metabolism
	Metabolism; Metabolism of cofactors and vitamins	Folate biosynthesis
	Metabolism; Metabolism of cofactors and vitamins	Vitamin B6 metabolism
	Metabolism; Metabolism of terpenoids and polyketides	Carotenoid biosynthesis
	Organismal systems; Endocrime system	Insulin signaling pathway
	Metabolism; Xenobiotics biodegradation and metabolism	Toluene degradation
Hindgut	Metabolism; Metabolism of cofactors and vitamins	Nicotinate and nicotinamide metabolism
	Environmental information processing; Membrane transport	Phosphotransferase system (PTS)
	Metabolism; Energy metabolism	Nitrogen metabolism
	Metabolism; Metabolism of cofactors and vitamins	Ubiquinone and other terpenoid-quinone biosynthesis
	Metabolism; Xenobiotics biodegradation and metabolism	Drug metabolism-other enzyme
	Genetic information processing; Replication and repair	DNA replication