title: Dietary lactosucrose suppresses influenza A (H1N1) virus infection in mice.
abstract: This study examined the effects of lactosucrose (4(G)-β-D-galactosylsucrose) on influenza A virus infections in mice. First, the effects of lactosucrose on fermentation in the cecum and on immune function were investigated. In female BALB/c mice, lactosucrose supplementation for 6 weeks promoted cecal fermentation and increased both secretory IgA (SIgA) levels in feces and total IgA and IgG2a concentrations in serum. Both the percentage of CD4(+) T cells in Peyer's patches and the cytotoxic activity of splenic natural killer (NK) cells increased significantly in response to lactosucrose. Next, we examined the effects of lactosucrose on low-dose influenza A virus infection in mice. After 2 weeks of dietary supplementation with lactosucrose, the mice were infected with low-dose influenza A virus. At 7 days post infection, a comparison with control mice showed that weight loss was suppressed, as were viral titers in the lungs. In the spleens of lactosucrose-fed mice, there was an increase in the percentage of NK cells. Lastly, mice fed lactosucrose were challenged with a lethal dose of influenza A virus. The survival rate of these mice was significantly higher than that of mice fed a control diet. These results suggested that lactosucrose supplementation suppresses influenza A virus infection by augmenting innate immune responses and enhancing cellular and mucosal immunity.
authors.affiliation: Carbohydrate Research Laboratory, Ensuiko Sugar Refining Co., Ltd., 1-1-1 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Kishino
authors.affiliation: Carbohydrate Research Laboratory, Ensuiko Sugar Refining Co., Ltd., 1-1-1 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Naho
authors.initials: N
authors.lastname: Takemura
authors.affiliation: Carbohydrate Research Laboratory, Ensuiko Sugar Refining Co., Ltd., 1-1-1 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Hisaharu
authors.initials: H
authors.lastname: Masaki
authors.affiliation: Carbohydrate Research Laboratory, Ensuiko Sugar Refining Co., Ltd., 1-1-1 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ito
authors.affiliation: Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakazawa
keywords: cytotoxic activity; lactosucrose; mucosal immunity; secretory IgA; serum IgA; splenic NK cells