Effects of Lactoferrin and Lactobacillus Supplementation on Immune Function, Oxidative Stress, and Gut Microbiota in Kittens

Abstract

Immune deficiency is a prevalent issue among kittens, severely threatening their health and development by increasing susceptibility to infections and diseases. This study investigates the effects of dietary supplements containing lactoferrin and Lactobacillus plantarum (L. plantarum) on the immune function, intestinal health, and microbiota composition of kittens. The results demonstrate that these supplements significantly enhance immune responses, with immunoglobulin A (IgA) levels increasing by 14.9% and IgG levels by 14.2%. Additionally, there was a notable 28.7% increase in catalase activity, indicating a reduction in oxidative stress. Gastrointestinal (GI) health improved markedly, evidenced by increased populations of beneficial bacteria such as Lactobacillus, which rose from 4.13% to 79.03% over the study period. The DNC group also showed significant reductions in pro-inflammatory cytokines, including decreases of 13.94% in IL-2, 26.46% in TNF-α, and 19.45% in IFN-γ levels. Furthermore, improvements in physical conditions were observed, including enhanced coat condition and mental status. These findings underline the potential of lactoferrin and L. plantarum as effective dietary interventions to improve kitten health, thereby reducing dependency on antibiotics and mitigating associated risks. This research provides a scientific foundation for optimizing nutritional management practices to enhance the overall vitality of kittens during their critical growth phases.

Keywords: Lactobacillus; gut microbiota; immune deficiency; kittens; lactoferrin.

Figure 1

Effects of dietary nutritional combinations on physical condition in kittens. (A) Coat condition scoring index, (B) mental status scoring index, (C) fecal scoring index, and (D) weight. The significant differences between the CON and DNC groups throughout the same feeding time are expressed as * p ≤ 0.05 and ** p ≤ 0.01 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON, control diet, dietary nutritional combinations not added, and DNC, addition of dietary nutritional combinations.

Figure 2

Effects of DNC on immunoglobulin parameters in kittens. (A) IgA, immunoglobulin A, (B) IgM, immunoglobulin M, and (C) IgG, immunoglobulin G. Significant differences between the CON and DNC groups throughout the same feeding time are expressed as * p ≤ 0.05 and ** p ≤ 0.01 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON, control diet, dietary nutritional combinations not added, and DNC, addition of dietary nutritional combinations.

Figure 3

Effects of DNC on antioxidant parameters in kittens. (A) T-AOC, total antioxidant capacity, (B) MDA, malondialdehyde, (C) CAT, catalase, (D) SOD, superoxide dismutase, and (E) GSH-PX, glutathione peroxidase. The significant differences between the CON and DNC groups throughout the same feeding time are expressed as * p ≤ 0.05, ** p ≤ 0.01, and *** p ≤ 0.001 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON, control diet, dietary nutritional combinations not added, and DNC, addition of dietary nutritional combinations.

Figure 4

Effects of DNC on cytokine level in kittens. (A) IL-2, interleukin-2, (B) IL-4, interleukin-4, (C) IFN-γ, interferon-γ, and (D) TNF-α, tumor necrosis factor-α. The significant differences between the CON and DNC groups throughout the same feeding time are expressed as ** p ≤ 0.01 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON, control diet, dietary nutritional combinations not added, and DNC, addition of dietary nutritional combinations.

Figure 5

Effects of DNC on plasma intestinal barrier function parameters in kittens. (A) D-LA, D-lactate and (B) DAO, diamine oxidase. The significant differences between the CON and DNC groups throughout the same feeding time are expressed as *** p ≤ 0.001 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON, control diet, dietary nutritional combinations not added, and DNC, addition of dietary nutritional combinations.

Figure 6

Effects of DNC on hair structural characteristics in kittens. (a) Hair scale thickness, (b) hair scale length, and (c) hair diameter. (A) CON0, (B) DNC0, (C) CON28, and (D) DNC28. The red arrow indicates the measuring position. The significant differences among all groups are expressed as ** p ≤ 0.01 and *** p ≤ 0.001 according to the paired-sample t-test. The values are expressed as means ± SD, n = 6. CON0, control diet, dietary nutritional combinations not added at day 0; DNC0, addition of dietary nutritional combinations at day 0; CON28, control diet, dietary nutritional combinations not added at day 28; and DNC28, addition of dietary nutritional combinations at day 28.

Figure 7

Effects of DNC on fecal microbiota composition in kittens. (A) Venn diagram, (B) principal coordinate analysis, (C) phylum level of bacteria, and (D) genus level of bacteria. The values are expressed as means ± SD, n = 6. CON0, control diet, dietary nutritional combinations not added at day 0; DNC0, addition of dietary nutritional combinations at day 0; CON28, control diet, dietary nutritional combinations not added at day 28; and DNC28, addition of dietary nutritional combinations at day 28.

Figure 8

Pearson’s correlation heatmap depicting the associations between bacterial profiles and serum indices. Correlations are color-coded, with blue representing positive associations and orange representing negative ones. The significance levels are * p ≤ 0.05, ** p ≤ 0.01, and *** p ≤ 0.001. Data are presented as mean ± SD, with a sample size of n = 6.