Question about small sample size

[UniAlberta]

I was wondering to ask about the sample size in each level of a categorical group for analyzing differentially abundant species. I only have 3 samples for each level. I can run ANCOMBC function as below. At the end, it says "You may have unstable results because of sample size <5". I wanted to know if my results are still reliable or if I need to look for another package.
output = ancombc2(data = tse, assay_name = "counts", tax_level = "Family",
fix_formula = "age + region + bmi", rand_formula = NULL,
p_adj_method = "holm", pseudo_sens = TRUE,
prv_cut = 0.10, lib_cut = 1000, s0_perc = 0.05,
group = "bmi", struc_zero = TRUE, neg_lb = TRUE,
alpha = 0.05, n_cl = 2, verbose = TRUE,
global = TRUE, pairwise = TRUE, dunnet = TRUE, trend = TRUE,
iter_control = list(tol = 1e-2, max_iter = 20,
verbose = TRUE),
em_control = list(tol = 1e-5, max_iter = 100),
lme_control = lme4::lmerControl(),
mdfdr_control = list(fwer_ctrl_method = "holm", B = 100),
trend_control = list(contrast = list(matrix(c(1, 0, -1, 1),
nrow = 2,
byrow = TRUE),
matrix(c(-1, 0, 1, -1),
nrow = 2,
byrow = TRUE),
matrix(c(1, 0, 1, -1),
nrow = 2,
byrow = TRUE)),
node = list(2, 2, 1),
solver = "ECOS",
B = 10))

[Maggie8888]

Since your sample size is too small most of the statistical test won't be stable. If you can somehow increase your sample size that will be a better way to solve the issue.

[UniAlberta]

Thanks for your reply. There`s no way to increase the sample size because they were taken from agricultural soils. So if I repeat ancombc2 with a low sample size multiple times and get the same result, can I trust them?