Involvement of estrogen in phosphorus-induced nephrocalcinosis through fibroblast growth factor 23.

Excessive phosphorus intake adversely affects bone and mineral metabolism. Estrogen is one of the factors affecting fibroblast growth factor 23 (FGF23), a phosphorus-regulating hormone. However, the interaction between excess phosphorus and estrogen status has not been fully elucidated. This study investigated the involvement of estrogen in the effects of high phosphorus intake on bone metabolism and ectopic calcification in ovariectomized (OVX) rats. The interaction between high phosphorus diet and OVX was not observed in bone mineral density and aortic calcium. In contrast, high phosphorus intake markedly increased renal calcium concentration in sham rats, whereas the effect was attenuated in OVX rats, which was reversed by a selective estrogen-receptor modulator treatment. A strong positive correlation between renal calcium and serum FGF23 was observed. In addition, fibroblast growth factor receptor 1 (FGFR1: a predominant receptor of FGF23) inhibitor treatment partially decreased renal calcium concentrations in rats with high phosphorus intake. In conclusion, the effect of high phosphorus intake on bone metabolism and aortic calcification did not depend on the estrogen status; in contrast, high phosphorus intake synergistically induced nephrocalcinosis in the presence of estrogenic action on the bone. Furthermore, FGF23 was involved in the nephrocalcinosis induced by high phosphorus intake partially through FGFR1 signaling.

Nutritional treatment with an immune-modulating enteral formula alleviates 5-fluorouracil-induced adverse effects in rats.

Cancer chemotherapy is frequently accompanied by adverse effects, such as diarrhoea and leukopenia, which lead to malnutrition and a decrease in the patients' quality of life. We previously demonstrated that an immune-modulating formula (IMF)-an enteral formula enriched with immunonutrients, whey-hydrolysed peptides, and fermented milk-had anti-inflammatory effects and protective effects on intestinal disorders in some experimental models. Here, we investigated whether nutritional treatment with the IMF could prevent 5-fluorouracil (5-FU)-induced adverse effects in rats. Rats were randomised into CTR and IMF groups, which received a control formula or the IMD supplemented formula ad libitum. Two weeks after starting the formula, rats were intraperitoneally injected with 5-FU (300 mg/kg) on day 0. The treatment with 5-FU decreased their body weights, food intake, and leukocyte counts, and worsened the diarrhoea score. However, the body weights, food intake, and leukocyte counts were significantly higher in the IMF rats than in the CTR rats on day 1. The IMF also delayed the incidence of diarrhoea and significantly preserved the villus heights in the jejunum on day 2. In conclusion, nutritional treatment with the IMF alleviated the adverse effects induced by 5-FU injection in rats.

The Effects of Mold-Fermented Cheese on Brain-Derived Neurotrophic Factor in Community-Dwelling Older Japanese Women With Mild Cognitive Impairment: A Randomized, Controlled, Crossover Trial.

OBJECTIVES: To investigate the effects of mold-fermented cheese (MFC) on brain-derived neurotrophic factor (BDNF) in community-dwelling older Japanese women with mild cognitive impairment (MCI). DESIGN: Randomized controlled crossover trial. INTERVENTION: Participants were randomly assigned to 2 groups. The MFC group was provided with 33.4 g MFC (camembert cheese) daily for 3 months, and the non-MFC group was provided with the same amount of non-MFC (processed cheese made from mozzarella cheese and cream cheese) for 3 months. After the post-intervention analysis (primary analysis), there was a 3-month washout period, followed by a crossover period (secondary analysis). SETTING AND PARTICIPANTS: Urban community in Tokyo, Japan. A total of 71 older women aged ≥70 years with MCI based on selected criteria in 689 community-dwelling women. MEASURES: Face-to-face interviews were conducted to administer the Geriatric Depression Scale (GDS) and Mini-Mental State Examination (MMSE) and collect data on medical history. Physical function measures included grip strength, knee extension strength, and usual walking speed. Blood samples were obtained to determine the levels of albumin, vitamin D, high-sensitivity C-reactive protein, and BDNF. RESULTS: Significant interactions were observed in BDNF after intervention of MFC intake in the secondary (F = 5.368, P = .024) and combined analyses (F = 4.354, P = .039) but not the primary analysis. There were no significant changes in the 3 categories of MMSE score (normal, MCI, moderate or severe cognitive impairment), GDS score, physical function, and blood indicators. CONCLUSIONS AND IMPLICATIONS: Three months of MFC ingestion had beneficial effects on BDNF levels in community-dwelling older women with MCI; however, the BDNF increases did not translate into MMSE scores. Further study into the effects of interventions on cognitive function and depression in older people with MCI is necessary.

Age-related and seasonal changes in covalently bound ceramide content in forearm stratum corneum of Japanese subjects: determination of molecular species of ceramides.

The stratum corneum (SC) consists of corneocytes surrounded by a neutral lipid-enriched intercellular matrix. Ceramides represent approximately 50% of intercellular lipids, and play important roles in retaining epidermal water. The SC also contains covalently bound ceramides, which are thought to play a crucial role in the formation of lamellar structures, and are involved in maintaining skin barrier function. A previous report showed that levels of free ceramides in human SC changed with the seasons and age, although whether the content of different species of covalently bound ceramides also underwent such temporal changes was unclear. Here, SC samples were taken from 99 healthy individuals of different ages (24-64 years) and during different seasons. The content of different molecular species of covalently bound ceramides in the samples was quantified using HPLC-MS/MS. The levels of total covalently bound ceramides (Total-Cers) significantly decreased approximately 50% in autumn and winter, compared with that of spring and summer. The levels of covalently bound ceramides containing saturated fatty acids (SFA-Cers) in the spring and summer were approximately 2.3-fold higher than that seen in autumn and winter, whereas the level of covalently bound ceramides containing unsaturated fatty acids (USFA-Cers) in spring and summer were approximately 1.6-fold higher than that in autumn and winter. Furthermore, the ratio between SFA-Cers and USFA-Cers was significantly lower in spring and summer than in autumn and winter. The levels of SFA-Cers, but not USFA-Cers, were significantly lower in individuals ≥ 50 years old compared to those who are 30- and 40-years old in the spring. Our study showed for the first time that, similar to free ceramides, the level of covalently bound ceramides changed with the seasons. However, age-related changes in covalently bound ceramide content were limited in that only the amount of SFA-Cers in the spring was lower in older individuals.

An immune-modulating formula comprising whey peptides and fermented milk improves inflammation-related remote organ injuries in diet-induced acute pancreatitis in mice.

It has been demonstrated that an immune-modulating enteral formula enriched with whey peptides and fermented milk (IMF) had anti-inflammatory effects in some experimental models when it was administered before the induction of inflammation. Here, we investigated the anti-inflammatory effects of the IMF administration after the onset of systemic inflammation and investigated whether the IMF could improve the remote organ injuries in an acute pancreatitis (AP) model. Mice were fasted for 12 hours and then fed a choline-deficient and ethionine-supplemented diet (CDE diet) for 24 hours to induce pancreatitis. In experiment 1, the diet was replaced with a control enteral formula, and mice were sacrificed at 24-hour intervals for 96 hours. In experiment 2, mice were randomized into control and IMF groups and received the control formula or the IMF respectively for 72 hr or 96 hr. In experiment 1, pancreatitis was induced by the CDE diet, and inflammatory mediators were elevated for several days. Remote organ injuries such as splenomegaly, hepatomegaly, and elevation of the hepatic enzymes developed. A significant strong positive correlation was observed between plasma MCP-1 and hepatic enzymes. In experiment 2, the IMF significantly improved splenomegaly, hepatomegaly, and the elevation of hepatic enzymes. Plasma MCP-1 levels were significantly lower in the IMF group than in the control group. Nutrition management with the IMF may be useful for alleviating remote organ injuries after AP.

Effects of dietary gelatin hydrolysates on bone mineral density in magnesium-deficient rats.

BACKGROUND: The major types of commercially available gelatin hydrolysates are prepared from mammals or fish. Dietary gelatin hydrolysates from mammals were reported to improve bone mineral density (BMD) in some animal models. In contrast, there is limited study showing the effects of dietary gelatin hydrolysates from fish on BMD. The quantity and structure of peptides in the plasma after oral administration of gelatin hydrolysates depend on the gelatin source, which suggests that the biological activity of gelatin hydrolysates depend on the gelatin source. This study examined the effects of fish-derived gelatin hydrolysate (FGH) or porcine-derived gelatin hydrolysate (PGH) intake on BMD and intrinsic biomechanical properties in magnesium (Mg)-deficient rats as a model showing the decrease in both BMD and intrinsic biomechanical properties. METHODS: Four-week-old male Wistar rats were assigned into four groups: a normal group was fed a normal diet (48 mg Mg/100 g diet), a Mg-deficient (MgD) group was fed a MgD diet (7 mg Mg/100 g diet), a FGH group was fed a MgD + FGH diet (5% FGH), and a PGH group was fed a MgD + PGH diet (5% PGH) for 8 weeks. At the end of the study, BMD and intrinsic biomechanical properties of the femur were measured. RESULTS: The MgD group showed significantly lower Young's modulus, an intrinsic biomechanical property, and trabecular BMD of the femur than the normal group; however, the MgD diet did not affect cortical BMD and cortical thickness. Both the FGH and the PGH groups showed significantly higher cortical thickness and ultimate displacement of the femur than the normal group, but neither type of gelatin hydrolysate affected Young's modulus. Furthermore, the FGH group, but not the PGH group, showed significantly higher trabecular BMD than the MgD group. CONCLUSIONS: This study indicates that FGH and PGH increase cortical thickness but only FGH prevents the decrease in trabecular BMD seen in Mg-deficient rats, while neither type of gelatin hydrolysate affect intrinsic biomechanical properties.

Milk Fermented by Lactic Acid Bacteria Enhances the Absorption of Dietary Sphingomyelin in Rats.

Supplementation with sphingomyelin has been reported to prevent disease and maintain good health. However, intact sphingomyelin and ceramides are poorly absorbed compared with glycerolipids. Therefore, if the bioavailability of dietary sphingomyelin can be increased, supplementation would be more effective at lower doses. The aim of this study in rats was to evaluate the effect of fermented milk on the bioavailability of dietary sphingomyelin in rats. After the rats had fasted for 15 h, test solutions were administrated orally. Blood samples were collected from the tail vein before and 90, 180, 270, and 360 min after administration. Compared with sphingomyelin/milk phospholipids concentrate (MPL) alone, co-ingestion of sphingomyelin/MPL with fermented milk caused an approximate twofold significant increase in serum ceramides containing d16:1 sphingosine with 16:0, 22:0, 23:0 and 24:0 fatty acids, which was derived from the ingested sphingomyelin. While nonfat milk also increased the serum levels of these ceramides, fermented milk was more effective. Co-ingestion of the upper layer of fermented milk or exopolysaccharide concentrate prepared from fermented milk significantly increased serum ceramide levels. X-ray diffraction analysis also showed addition of fermented milk or EPS concentrate to sphingomyelin eliminated the characteristic peak of sphingomyelin. This study demonstrated for the first time that co-ingestion of dietary sphingomyelin and fermented milk, compared with ingestion of dietary sphingomyelin alone, caused a significant increase in the absorption of sphingomyelin. Our results indicate exopolysaccharides in fermented milk may contribute to inhibition of sphingomyelin crystallization, resulting in enhanced absorption of dietary sphingomyelin in rats.

Exopolysaccharides Isolated from Milk Fermented with Lactic Acid Bacteria Prevent Ultraviolet-Induced Skin Damage in Hairless Mice.

BACKGROUND: We studied the mechanism by which fermented milk ameliorates UV-B-induced skin damage and determined the active components in milk fermented with lactic acid bacteria by evaluating erythema formation, dryness, epidermal proliferation, DNA damage and cytokine mRNA levels in hairless mice exposed to acute UV-B irradiation. METHODS: Nine week-old hairless mice were given fermented milk (1.3 g/kg BW/day) or exopolysaccharide (EPS) concentrate (70 mg/kg BW/day) orally for ten days. Seven days after fermented milk or EPS administration began, the dorsal skin of the mice was exposed to a single dose of UV-B (20 mJ/cm²). RESULTS: Ingestion of either fermented milk or EPS significantly attenuated UV-B-induced erythema formation, dryness and epidermal proliferation in mouse skin. Both fermented milk and EPS were associated with a significant decrease in cyclobutane pyrimidine dimers and upregulated mRNA levels of xeroderma pigmentosum complementation group A (XPA), which is involved in DNA repair. Furthermore, administration of either fermented milk or EPS significantly suppressed increases in the ratio of interleukin (IL)-10/IL-12a and IL-10/interferon-gamma mRNA levels. CONCLUSION: Together, these results indicate that EPS isolated from milk fermented with lactic acid bacteria enhanced DNA repair mechanisms and modulated skin immunity to protect skin against UV damage.

Effects of Proton Pump Inhibitor Administration and Intake of a Combination of Yogurt and Galactooligosaccharides on Bone and Mineral Metabolism in Rats.

The aim of this study was to investigate the effects of proton pump inhibitor (PPI), the most potent acid-suppressing drug, administration and intake of a combination of yogurt and galactooligosaccharides (YG) on bone and mineral metabolism in adult rats. Twelve-week-old male Wistar rats were divided into three groups: a control group fed the control diet with vehicle administration, a PPI group fed the control diet with PPI administration and a YG + PPI group fed the YG diet with PPI administration. All of the groups received their respective experimental diets and daily subcutaneous injection of the vehicle or PPI for 12 weeks. The PPI group showed significantly lower bone mineral density (BMD) of the femur and the lumbar vertebrae and serum fibroblast growth factor 23 (FGF23) and significantly higher phosphorus absorption and serum 1,25-dihydroxyvitamin D (1,25(OH)2D) than the control group, although PPI did not affect calcium absorption. The PPI + YG group showed significantly higher BMD and serum FGF23 and significantly lower phosphorus absorption and serum 1,25(OH)2D than the PPI group. Furthermore, the PPI + YG group showed higher calcium absorption than the control group. These results suggest that although PPI administration did not affect calcium absorption, it adversely affected BMD and influenced phosphorus metabolism in adult rats. Furthermore, the YG diet beneficially affected BMD and attenuated the effects of PPI administration on phosphorus metabolism.

Whey protein hydrolysates enhance water absorption in the perfused small intestine of anesthetized rats.

We evaluated the effect of whey protein hydrolysates (WPH) on the water absorption rate in the small intestine using a rat small intestine perfusion model. The rate was significantly higher with 5 g/L WPH than with 5 g/L soy protein hydrolysates or physiological saline (p < 0.05). WPH dose-dependently increased the water absorption rate in the range of 1.25-10.0 g/L. WPH showed a significantly higher rate than an amino acid mixture whose composition was equal to that of WPH (p < 0.05). The addition of 4-aminomethylbenzoic acid, an inhibitor of PepT1, significantly suppressed WPH's enhancement of water absorption (p < 0.05). The rate of water absorption was significantly correlated with that of peptides/amino acids absorption in WPH (r = 0.82, p < 0.01). These data suggest that WPH have a high water absorption-promoting effect, to which PepT1 contributes.

Enhanced vaccination effect against influenza by prebiotics in elderly patients receiving enteral nutrition.

AIM: We investigated the effect of prebiotics on the immunological response after influenza vaccination in enterally fed elderly individuals. The intervention group was given an enteral formula containing lactic acid bacteria-fermented milk products. In addition, two different types of other prebiotics, galacto-oligosaccharide and bifidogenic growth stimulator, were also given. The two prebiotics improved intestinal microbiota differently. In a control group, a standard formula without prebiotics was given. METHODS: An enteral formula with (intervention group [F]) or without (control group [C]) prebiotics was given through percutaneous endoscopic gastrostomy to elderly participants for 10 weeks. Influenza vaccine was inoculated at week 4. Nutritional and biochemical indices, intestinal micro bacteria and immunological indices were analyzed. RESULTS: The Bifidobacterium count in groups F and C at week 0 was 6.4 ± 1.9 and 6.6 ± 3.0 (log10 [count/g feces]), respectively. Although the count in group C decreased at week 10, the count in group F increased. The Bacteroides count in group F increased from 10.7 ± 0.9 to 11.4 ± 0.5, but decreased in group C from 11.2 ± 0.2 to 10.7 ± 0.4. Although the enhanced titers of H1N1, H3N2 and B antigens against the vaccine decreased thereafter in group C, these enhanced titers in group F could be maintained. CONCLUSION: Our findings suggest that prebiotics affect the intestinal microbiota and might maintain the antibody titers in elderly individuals.

Effects of 5-aminolevulinic acid on a murine model of diet-induced obesity.

The effects of 5-aminolevulinic acid (5-ALA) on obesity were investigated using a murine model (diet-induced obese mice). Diet-induced obese mice were divided into 4 groups: a control group (C group), which was fed a high-fat diet; a low-5-ALA dose (10 mg/kg/day) group (10A group); a moderate-5-ALA dose (30 mg/kg/day) group (30A group); and a high-5-ALA dose (100 mg/kg/day) group (100A group). 5-ALA was administered by mixing the high fat diet for 8 weeks. Body weight increases in the 30A and 100A groups were significantly smaller compared with those of the C group. Body fat measurements by X-ray computed tomography indicated that the 100A group showed a tendency toward low visceral fat quantities during the final week of the study. Visceral fat weights in the 30A and 100A groups were slightly low. The levels of serum alanine aminotransferase (ALT) and total cholesterol (TC) in the 10A group was slightly low, whereas the 30A and 100A groups showed significantly lower ALT and TC values. Liver lipid concentration showed a dose-dependent decrease with ALA. Thus, in this diet-induced obese murine model, administration of 5-ALA had a significantly beneficial impact on the visceral fat, serum ALT and TC, and liver lipid concentration.

Increased Milk Protein Concentration in a Rehydration Drink Enhances Fluid Retention Caused by Water Reabsorption in Rats.

A fluid-retention effect is required for beverages that are designed to prevent dehydration. That is, fluid absorbed from the intestines should not be excreted quickly; long-term retention is desirable. Here, we focused on the effect of milk protein on fluid retention, and propose a new effective oral rehydration method that can be used daily for preventing dehydration. We first evaluated the effects of different concentrations of milk protein on fluid retention by measuring the urinary volumes of rats fed fluid containing milk protein at concentrations of 1, 5, and 10%. We next compared the fluid-retention effect of milk protein-enriched drink (MPD) with those of distilled water (DW) and a sports drink (SD) by the same method. Third, to investigate the mechanism of fluid retention, we measured plasma insulin changes in rats after ingesting these three drinks. We found that the addition of milk protein at 5 or 10% reduced urinary volume in a dose-dependent manner. Ingestion of the MPD containing 4.6% milk protein resulted in lower urinary volumes than DW and SD. MPD also showed a higher water reabsorption rate in the kidneys and higher concentrations of plasma insulin than DW and SD. These results suggest that increasing milk protein concentration in a beverage enhances fluid retention, which may allow the possibility to develop rehydration beverages that are more effective than SDs. In addition, insulin-modifying renal water reabsorption may contribute to the fluid-retention effect of MPD.

Milk Phospholipids Enhance Lymphatic Absorption of Dietary Sphingomyelin in Lymph-Cannulated Rats.

Supplementation with sphingomyelin has been reported to have beneficial effects on disease prevention and health maintenance. However, compared with glycerolipids, intact sphingomyelin and ceramides are poorly absorbed. Therefore, if the bioavailability of dietary sphingomyelin is increased, then the dose administered can be reduced. This study was designed to identify molecular species of ceramide in rat lymph after the ingestion of milk sphingomyelin, and to compare the effect of purified sphingomyelin with milk phospholipids concentrate (MPL, 185 mg sphingomyelin/g) on lymphatic absorption of milk sphingomyelin. Lymph was collected hourly for 6 h from lymph-cannulated rats (n = 8/group) after the administration of a control emulsion (triolein, bovine serum albumin, and sodium taurocholate), a sphingomyelin emulsion (control + purified sphingomyelin), or a MPL emulsion (control + MPL). Molecular species of ceramide in lymph were analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Molecular species of ceramide, containing not only d18:1, but also d17:1 and d16:1 sphingosine with 16:0, 22:0, 23:0, and 24:0 fatty acids (specific to milk sphingomyelin), were increased in rat lymph after the administration of milk sphingomyelin. Their molecular species were similar to those of dietary milk sphingomyelin. Recovery of ceramide moieties from dietary sphingomyelin was 1.28- to 1.80-fold significantly higher in the MPL group than in the sphingomyelin group. Our results demonstrated that dietary sphingomyelin from milk was transported to lymph as molecular species of ceramide hydrolyzed from milk sphingomyelin and co-ingestion of sphingomyelin with glycerophospholipids enhanced the bioavailability of dietary sphingomyelin.

Dietary Milk Sphingomyelin Prevents Disruption of Skin Barrier Function in Hairless Mice after UV-B Irradiation.

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm2). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

An Immune-Modulating Diet in Combination with Chemotherapy Prevents Cancer Cachexia by Attenuating Systemic Inflammation in Colon 26 Tumor-Bearing Mice.

Cancer cachexia is characterized by muscle wasting caused partly by systemic inflammation. We previously demonstrated an immune-modulating diet (IMD), an enteral diet enriched with immunonutrition and whey-hydrolyzed peptides, to have antiinflammatory effects in some experimental models. Here, we investigated whether the IMD in combination with chemotherapy could prevent cancer cachexia in colon 26 tumor-bearing mice. Forty tumor-bearing mice were randomized into 5 groups: tumor-bearing control (TB), low dose 5-fluorouracil (5-FU) and standard diet (LF/ST), low dose 5-FU and IMD (LF/IMD), high dose 5-FU and standard diet (HF/ST) and high dose 5-FU and IMD (HF/IMD). The ST and IMD mice received a standard diet or the IMD ad libitum for 21 days. Muscle mass in the IMD mice was significantly higher than that in the ST mice. The LF/IMD in addition to the HF/ST and HF/IMD mice preserved their body and carcass weights. Plasma prostaglandin E2 levels were significantly lower in the IMD mice than in the ST mice. A combined effect was also observed in plasma interleukin-6, glucose, and vascular endothelial growth factor levels. Tumor weight was not affected by different diets. In conclusion, the IMD in combination with chemotherapy prevented cancer cachexia without suppressing chemotherapeutic efficacy.

Whey peptide-based enteral diet attenuated elastase-induced emphysema with increase in short chain fatty acids in mice.

BACKGROUND: Systemic inflammation is present in chronic obstructive pulmonary disease (COPD). A whey peptide-based enteral diet reduce inflammation in patients with COPD, but its effect on COPD development has not been determined. On the other hand, it is known that short chain fatty acids (SCFAs), which are produced by micro-flora in the gut, attenuates bronchial asthma in mice model. METHODS: Mice with elastase-induced emphysema were fed with 1 of 3 diets (control diet, whey peptide-based enteral diet, or standard enteral diet) to determine the effects of whey peptide-based enteral diet on emphysema and on cecal SCFAs. RESULTS: The whey peptide-based enteral diet group exhibited fewer emphysematous changes; significantly lower total cell counts in bronchoalveolar lavage fluid (BALF); and significantly higher cecal SCFA levels than either the control or standard enteral diet groups. The total cell count was inversely correlated with total cecal SCFA levels in these three diet groups. CONCLUSIONS: The whey peptide-based enteral diet attenuates elastase-induced emphysema through the suppression of inflammation in the lung. This may be related to the increase in cecal SCFA.

Effects of a Formula Containing Two Types of Prebiotics, Bifidogenic Growth Stimulator and Galacto-oligosaccharide, and Fermented Milk Products on Intestinal Microbiota and Antibody Response to Influenza Vaccine in Elderly Patients: A Randomized Controlled Trial.

We investigated the effect of a formula containing two different prebiotics (bifidogenic growth stimulator and galacto-oligosaccharide) and fermented milk products on intestinal microbiota and antibody responses to an influenza vaccine in enterally fed elderly in-patients. Patients were administered either formula containing prebiotics and fermented milk products (group F: n = 12, 79.9 ± 9.5 years old) or standard formula (group C: n = 12, 80.7 ± 10.1 years old) via percutaneous endoscopic gastrostomy during a 14-week intervention period. Subjects were immunized with an influenza vaccine (A/H1N1, A/H3N2, and B) at week 4 of the intervention. Blood biochemical indices, intestinal bacteria populations and antibody titers were analyzed. Bifidobacterium counts increased significantly in group F compared with group C. The enhanced antibody titers against A/H1N1 were maintained in group F for a longer period compared with group C. The titers against A/H3N2 were unchanged between both groups, and those against B were significantly lower in group F than in group C, although few subjects had seroprotective titers against A/H3N2 and B. These results suggest that administration of the formula containing prebiotics and fermented milk products may maintain antibody titers for longer periods through the improvement of intestinal microbiota.