Table 1.

Main effects of probiotic, prebiotic, and synbiotic treatments on patients with NAFLD.

Type of Treatment	Characterization of the Studied Population/Dietary Recommendations	Composition	Dosage	Effects	Ref.
Probiotic	n = 65 m/f ratio = 1.03 Patients with BMI > 25 kg/m2 diagnosed with NAFLD, between 19 to 75 years old. The patients were educated on appropriate daily nutritional intake and exercise.	L. acidophilus CBT LA1 L. rhamnosus CBT LR5 L. paracasei CBT LPC5 P. pentosaceus CBT SL4 B. lactis CBT BL3 B. breve CBT BR3	109 CFU/day of probiotic strains, for 12 weeks.	↑ L. acidophilus, L. rhamnosus, P. pentosaceus, B. lactis and B. breve ↑ Agathobaculum, Dorea (OTU 527923), Dorea (OTU 195044), Blautia, Ruminococcus, and Dorea (OTU 470168). ↓ Intrahepatic fat fraction ↓ TC, TG ↓ BMI, weight ↓ Total fat mass, % total body fat and visceral fat ↓ TNF-α	[26]
	n = 92 Only female patients with BMI ≥ 28 kg/m2 diagnosed with NAFLD and MetS, between 36 and 66 years old.	L. delbrueckii subsp. bulgaricus S. thermophilus	220 g of yogurt/day, for 24 weeks.	↓ Firmicutes, Clostridia and Erysipelotrichia ↓ Clostridiales and Erysipelotrichales ↓ Erysipelotrichaceae and Veillonellaceae ↓ Blautia, Pseudobutyrivibrio, Eubacterium ventriosum, Ruminococcus and Dialister ↑ Negativicutes, Selenomonadales, Acidaminococcaceae and Phascolarctobacterium. ↓ LPS ↓ ALT ↓ Fat mass ↓ TC, TG ↓ FBS ↓ Fasting insulin, HOMA-IR ↓ TNF-α	[27]
	n = 3 m/f ratio = n.s. Patients diagnosed with NAFLD, ≥18 years old. The patients were advised to follow a healthy lifestyle, and patients with overweight/obesity were advised to follow a hypocaloric diet (30% reduction in calorie intake).	L. paracasei DSM 24733 L. plantarum DSM 24730 L. acidophilus DSM 24735 L. delbrueckii subsp. bulgaricus DSM 24734 B. longum DSM 24736 B. infantis DSM 24737 B. breve DSM 24732 S. thermophilus DSM 24731	2 × 1011 CFU/day of probiotic strains, for 12 months.	↓ Endotoxins ↓ NAS ↓ Steatohepatitis ↓ ALP, AST, ALT ↓ TNF-α, IL-1β, IL-6	[28]
	n = 58 m/f ratio n.s. Patients with BMI > 25 kg/m2 diagnosed with NAFLD and type 2 diabetes, between 18 and 65 years old. The patients were advised to follow a healthy lifestyle and to continue with their antihyperglycemic treatment.	Lactobacillus Lactococcus Bifidobacterium Propionibacterium Acetobacter	6 × 1010 CFU/day of Lactobacillus and Lactococcus + 1 × 1010 CFU/day of Bifidobacterium + 3 × 1010 CFU/day of Propionibacterium + 1 × 106 CFU/day of Acetobacter, for 8 weeks.	↓ Fatty Liver Index ↓ AST, GGT ↓ TC, TG, LDL-C ↓ TNF-α, IL-6	[29]
	n = 72 m/f ratio = 0.95 Patients with BMI between 25 and 40 kg/m2 diagnosed with NASH, between 23 and 40 years old.	L. bulgaricus L. acidophilus B. lactis S. thermophilus	300 g of yogurt/day of probiotic strains, for 8 weeks.	↓ BMI, weight	[30]
	n = 42 m/f ratio = 2.00 Patients diagnosed with NAFLD, between 18 and 65 years old.	L. casei L. acidophilus L. rhamnosus L. bulgaricus B. breve B. longum S. thermophilus	3 × 109 CFU/day of L. casei + 3 × 1010 CFU/day of L. acidophilus + 7 × 109 CFU/day of L. rhamnosus + 5 × 108 CFU/day of L. bulgaricus + 2 × 1010 CFU/day of B. breve + 1 × 109 CFU/day of B. longum + 3 × 108 CFU/day of S. thermophilus, for 8 weeks.	↓ TNF-α, IL-6 ↓ FBS ↓ Insulin, HOMA-IR	[31]
Prebiotic	n = 60 m/f ratio = n.s. Patients with BMI > 27 kg/m2 diagnosed with NAFLD and type 2 diabetes or MetS, between 18 to 75 years old. The patients were advised to follow a healthy lifestyle and diet.	Inulin	4 g of inulin/day, for 4 weeks	↓ ALT	[32]
	n = 14 m/f ratio = 1.00 Patients with BMI > 23 kg/m2 diagnosed with NASH, ≥18 years old.	FOS	8 g of FOS/day, for 12 weeks, then, 16 g/day, for 24 weeks.	↑ Bifidobacterium ↓ Clostridium cluster XI and I ↓ Hepatic steatosis ↓ NAS	[33]
Synbiotic	n = 89 m/f = 1.90 Patients diagnosed with NAFLD.	FOS B. animalis subsp. lactis BB-12	8 g of FOS/day + 109 CFU/day of probiotic strain, for 10–14 months.	↑ Bifidobacterium and Faecalibacterium ↓ Oscillibacter and Alistipes	[12]
	n = 75 m/f ratio = 0.56 Patients diagnosed with NASH, ≥18 years old. Low-fat/low-calorie food plan	FOS L. casei L. rhamnosus L. bulgaris B. longum S. thermophilus	FOS (n.s.) + 108 CFU/day of probiotic strains, for 12 weeks.	↑ Bifidobacterium, Lactobacillus, non-pathogenic E. coli and Enterococcus faecalis ↓ ALT, AST ↓ TC ↓ BMI	[34]
	n = 50 m/f ratio = 0.58 Patients diagnosed with NASH, between 25 to 74 years old. Food plan of 1500 kcal/day for women and 1800 kcal/day for men	Guar gum Inulin L. reuteri	8 g of partially hydrolyzed guar gum and inulin/day + 2 × 108 CFU/day of probiotic strain, for 3 months.	↑ LPS ↓ Hepatic steatosis ↓ BMI, WC	[35]
	n = 102 m/f ratio = 0.96 Patients diagnosed with NAFLD, ≥18 years old. The patients were advised to follow a healthy lifestyle.	Inulin Bifidobacterium animalis subsp. lactis (BB-12)	1.5 g inulin/day + 300 g of yogurt supplemented with 108 CFU/day of probiotic strain, for 24 weeks.	↓ Grade of fatty liver ↓ AST, ALT, ALP, GGT ↓ TC, TG, LDL-C	[36]
	n = 60 m/f ratio = 4.00 Patients with BMI between 25 and 35 kg/m2 diagnosed with NAFLD, between 25 and 64 years old.	FOS L. casei L. rhamnosus L. acidophilus L. bulgaricus B. breve B. longum S. thermophilus	FOS (n.s.) + 4 × 108 CFU/day of probiotic strains, for 8 weeks.	↓ ALT, AST, ALP ↓ TC, TG, LDL-C ↓ FBS, Insulin	[37]
	n = 60 m/f ratio = 4.00 Patients with BMI between 25 and 35 kg/m2 diagnosed with NAFLD, between 25 and 64 years old.	FOS L. casei L. rhamnosus L. acidophilus L. bulgaricus B. breve B. longum S. thermophilus	FOS (n.s.) + 4 × 108 CFU/day of probiotic strains, for 8 weeks.	↓ ALT, AST, ALP ↓ TNF-α	[38]
	n = 42 m/f ratio = 1.21 Patients with BMI ≤ 25 kg/m2 diagnosed with NAFLD, ≥18 years old. The patients were advised to follow a healthy lifestyle.	FOS L. casei L. rhamnosus L. acidophilus L. bulgaricus B. breve B. longum S. thermophilus	125 mg of FOS/day + 2 × 108 CFU/day of probiotic strains, for 28 weeks	↓ Hepatic steatosis and fibrosis ↓ AST, ALT, GGT ↓ TNF-α, NF-κB ↓ FBS	[39]
	n = 75 m/f ratio = 4.00 Patients diagnosed with NAFLD, between 20 and 60 years old.	HP inulin B. longum L. acidophilus	10 g/day of HP inulin + 2 × 107 CFU/day of probiotic strains, for 3 months	↓ Grade of fatty liver ↓ AST, ALT, ALP	[40]
	n = 74 m/f ratio = 0.35 Patients diagnosed with NAFLD, between 18 and 60 years old.	FOS L. casei L. acidophilus L. rhamnosus L. bulgaricus B. breve B. longum S. thermophilus	500 mg/day of the synbiotic mixture, for 8 weeks.	↓ TC, LDL-C ↓ Weight ↓ Fat mass	[41]
	n = 75 m/f ratio = 4.00 Patients diagnosed with NAFLD, between 20 and 60 years old.	Inulin L. acidophilus B. longum	10 g/day of inulin + 107 CFU/day of probiotic strains, for 3 months.	↓ BMI ↓ WC ↓ ALT, AST ↓ TNF-α	[42]
	n = 74 m/f ratio = 0.35 Patients diagnosed with NAFLD, between 18 and 60 years old.	FOS L. casei L. acidophilus L. rhamnosus L. bulgaricus B. breve B. longum S. thermophilus	500 mg/day synbiotic mixture, for 8 weeks.	↓ Steatosis	[43]

CFU: colony forming units, TC: total cholesterol, TG: triglycerides, LPS: lipopolysaccharides, ALT: alanine aminotransferase, AST: aspartate aminotransferase, GGT: gamma-glutamyl transferase, ALP: alkaline phosphatase, BMI: body mass index, NAS: NAFLD activity score, TNF-α: tumor necrosis factor alpha, NF-κB: nuclear factor κB, IL-1β: interleukin 1β, IL-6: interleukin 6, LDL-C: low density lipoprotein–cholesterol, WC: waist circumference, FBS: fasting blood sugar, HOMA-IR: homeostatic model assessment–insulin resistance, BMI: body mass index, m/f ratio: male/female ratio, n.s.: not specified.