knitr::opts_chunk$set(message = FALSE, warning = FALSE, comment = NA, 
                      fig.width = 6.25, fig.height = 5)
library(ANCOMBC)
library(tidyverse)Sparse Estimation of Correlations among Microbiomes (SECOM) (Lin, Eggesbø, and Peddada 2022) is a methodology that aims to detect both linear and nonlinear relationships between a pair of taxa within an ecosystem (e.g., gut) or across ecosystems (e.g., gut and tongue). SECOM corrects both sample-specific and taxon-specific biases and obtains a consistent estimator for the correlation matrix of microbial absolute abundances while maintaining the underlying true sparsity. For more details, please refer to the SECOM paper.
Download package.
if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")
BiocManager::install("ANCOMBC")Load the package.
The HITChip Atlas dataset contains genus-level microbiota profiling with HITChip for 1006 western adults with no reported health complications, reported in (Lahti et al. 2014). The dataset is available via the microbiome R package (Lahti et al. 2017) in phyloseq (McMurdie and Holmes 2013) format.
data(atlas1006, package = "microbiome")
tse = mia::makeTreeSummarizedExperimentFromPhyloseq(atlas1006)
# subset to baseline
tse = tse[, tse$time == 0]
# Re-code the bmi group
tse$bmi = recode(tse$bmi_group,
                 obese = "obese",
                 severeobese = "obese",
                 morbidobese = "obese")
# Subset to lean, overweight, and obese subjects
tse = tse[, tse$bmi %in% c("lean", "overweight", "obese")]
# Create the region variable
tse$region = recode(as.character(tse$nationality),
                    Scandinavia = "NE", UKIE = "NE", SouthEurope = "SE", 
                    CentralEurope = "CE", EasternEurope = "EE",
                    .missing = "unknown")
# Discard "EE" as it contains only 1 subject
# Discard subjects with missing values of region
tse = tse[, ! tse$region %in% c("EE", "unknown")]
print(tse)class: TreeSummarizedExperiment 
dim: 130 873 
metadata(0):
assays(1): counts
rownames(130): Actinomycetaceae Aerococcus ... Xanthomonadaceae
  Yersinia et rel.
rowData names(3): Phylum Family Genus
colnames(873): Sample-1 Sample-2 ... Sample-1005 Sample-1006
colData names(12): age sex ... bmi region
reducedDimNames(0):
mainExpName: NULL
altExpNames(0):
rowLinks: NULL
rowTree: NULL
colLinks: NULL
colTree: NULLset.seed(123)
# Linear relationships
res_linear = secom_linear(data = list(tse), assay_name = "counts",
                          tax_level = "Phylum", pseudo = 0, 
                          prv_cut = 0.5, lib_cut = 1000, corr_cut = 0.5, 
                          wins_quant = c(0.05, 0.95), method = "pearson", 
                          soft = FALSE, thresh_len = 20, n_cv = 10, 
                          thresh_hard = 0.3, max_p = 0.005, n_cl = 2)
# Nonlinear relationships
res_dist = secom_dist(data = list(tse), assay_name = "counts",
                      tax_level = "Phylum", pseudo = 0, 
                      prv_cut = 0.5, lib_cut = 1000, corr_cut = 0.5, 
                      wins_quant = c(0.05, 0.95), R = 1000, 
                      thresh_hard = 0.3, max_p = 0.005, n_cl = 2)corr_linear = res_linear$corr_th
cooccur_linear = res_linear$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_linear[cooccur_linear < overlap] = 0
df_linear = data.frame(get_upper_tri(corr_linear)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(value = round(value, 2))
tax_name = sort(union(df_linear$var1, df_linear$var2))
df_linear$var1 = factor(df_linear$var1, levels = tax_name)
df_linear$var2 = factor(df_linear$var2, levels = tax_name)
heat_linear_th = df_linear %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", na.value = "grey",
                       midpoint = 0, limit = c(-1,1), space = "Lab", 
                       name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Pearson (Thresholding)") +
  theme_bw() +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic"),
        axis.text.y = element_text(size = 12, face = "italic"),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_linear_thcorr_linear = res_linear$corr_fl
cooccur_linear = res_linear$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_linear[cooccur_linear < overlap] = 0
df_linear = data.frame(get_upper_tri(corr_linear)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(value = round(value, 2))
tax_name = sort(union(df_linear$var1, df_linear$var2))
df_linear$var1 = factor(df_linear$var1, levels = tax_name)
df_linear$var2 = factor(df_linear$var2, levels = tax_name)
heat_linear_fl = df_linear %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", na.value = "grey",
                       midpoint = 0, limit = c(-1,1), space = "Lab", 
                       name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Pearson (Filtering)") +
  theme_bw() +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic"),
        axis.text.y = element_text(size = 12, face = "italic"),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_linear_flcorr_dist = res_dist$dcorr_fl
cooccur_dist = res_dist$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_dist[cooccur_dist < overlap] = 0
df_dist = data.frame(get_upper_tri(corr_dist)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(value = round(value, 2))
tax_name = sort(union(df_dist$var1, df_dist$var2))
df_dist$var1 = factor(df_dist$var1, levels = tax_name)
df_dist$var2 = factor(df_dist$var2, levels = tax_name)
heat_dist_fl = df_dist %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", na.value = "grey",
                       midpoint = 0, limit = c(-1,1), space = "Lab", 
                       name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Distance (Filtering)") +
  theme_bw() +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic"),
        axis.text.y = element_text(size = 12, face = "italic"),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_dist_flTo compute correlations whithin and across different ecosystems, one needs to make sure that there are samples in common across these ecosystems.
# Select subjects from "CE" and "NE"
tse1 = tse[, tse$region == "CE"]
tse2 = tse[, tse$region == "NE"]
# Rename samples to ensure there is an overlap of samples between CE and NE
colnames(tse1) = paste0("Sample-", seq_len(ncol(tse1)))
colnames(tse2) = paste0("Sample-", seq_len(ncol(tse2)))
print(tse1)class: TreeSummarizedExperiment 
dim: 130 578 
metadata(0):
assays(1): counts
rownames(130): Actinomycetaceae Aerococcus ... Xanthomonadaceae
  Yersinia et rel.
rowData names(3): Phylum Family Genus
colnames(578): Sample-1 Sample-2 ... Sample-577 Sample-578
colData names(12): age sex ... bmi region
reducedDimNames(0):
mainExpName: NULL
altExpNames(0):
rowLinks: NULL
rowTree: NULL
colLinks: NULL
colTree: NULLclass: TreeSummarizedExperiment 
dim: 130 181 
metadata(0):
assays(1): counts
rownames(130): Actinomycetaceae Aerococcus ... Xanthomonadaceae
  Yersinia et rel.
rowData names(3): Phylum Family Genus
colnames(181): Sample-1 Sample-2 ... Sample-180 Sample-181
colData names(12): age sex ... bmi region
reducedDimNames(0):
mainExpName: NULL
altExpNames(0):
rowLinks: NULL
rowTree: NULL
colLinks: NULL
colTree: NULLset.seed(123)
# Linear relationships
res_linear = secom_linear(data = list(CE = tse1, NE = tse2), 
                          assay_name = c("counts", "counts"),
                          tax_level = c("Phylum", "Phylum"), pseudo = 0, 
                          prv_cut = 0.5, lib_cut = 1000, corr_cut = 0.5, 
                          wins_quant = c(0.05, 0.95), method = "pearson", 
                          soft = FALSE, thresh_len = 20, n_cv = 10, 
                          thresh_hard = 0.3, max_p = 0.005, n_cl = 2)
# Nonlinear relationships
res_dist = secom_dist(data = list(CE = tse1, NE = tse2),
                      assay_name = c("counts", "counts"),
                      tax_level = c("Phylum", "Phylum"), pseudo = 0, 
                      prv_cut = 0.5, lib_cut = 1000, corr_cut = 0.5, 
                      wins_quant = c(0.05, 0.95), R = 1000, 
                      thresh_hard = 0.3, max_p = 0.005, n_cl = 2)corr_linear = res_linear$corr_th
cooccur_linear = res_linear$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_linear[cooccur_linear < overlap] = 0
df_linear = data.frame(get_upper_tri(corr_linear)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(var2 = gsub("\\...", " - ", var2),
         value = round(value, 2))
tax_name = sort(union(df_linear$var1, df_linear$var2))
df_linear$var1 = factor(df_linear$var1, levels = tax_name)
df_linear$var2 = factor(df_linear$var2, levels = tax_name)
txt_color = ifelse(grepl("CE", tax_name), "#1B9E77", "#D95F02")
heat_linear_th = df_linear %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", 
                       na.value = "grey", midpoint = 0, limit = c(-1,1), 
                       space = "Lab", name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Pearson (Thresholding)") +
  theme_bw() +
  geom_vline(xintercept = 6.5, color = "blue", linetype = "dashed") +
  geom_hline(yintercept = 6.5, color = "blue", linetype = "dashed") +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic", color = txt_color),
        axis.text.y = element_text(size = 12, face = "italic", 
                                   color = txt_color),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_linear_thcorr_linear = res_linear$corr_th
cooccur_linear = res_linear$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_linear[cooccur_linear < overlap] = 0
df_linear = data.frame(get_upper_tri(corr_linear)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(var2 = gsub("\\...", " - ", var2),
         value = round(value, 2))
tax_name = sort(union(df_linear$var1, df_linear$var2))
df_linear$var1 = factor(df_linear$var1, levels = tax_name)
df_linear$var2 = factor(df_linear$var2, levels = tax_name)
txt_color = ifelse(grepl("CE", tax_name), "#1B9E77", "#D95F02")
heat_linear_fl = df_linear %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", 
                       na.value = "grey", midpoint = 0, limit = c(-1,1), 
                       space = "Lab", name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Pearson (Filtering)") +
  theme_bw() +
  geom_vline(xintercept = 6.5, color = "blue", linetype = "dashed") +
  geom_hline(yintercept = 6.5, color = "blue", linetype = "dashed") +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic", color = txt_color),
        axis.text.y = element_text(size = 12, face = "italic", 
                                   color = txt_color),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_linear_flcorr_dist = res_dist$dcorr_fl
cooccur_dist = res_dist$mat_cooccur
# Filter by co-occurrence
overlap = 10
corr_dist[cooccur_dist < overlap] = 0
df_dist = data.frame(get_upper_tri(corr_dist)) %>%
  rownames_to_column("var1") %>%
  pivot_longer(cols = -var1, names_to = "var2", values_to = "value") %>%
  filter(!is.na(value)) %>%
  mutate(var2 = gsub("\\...", " - ", var2),
         value = round(value, 2))
tax_name = sort(union(df_dist$var1, df_dist$var2))
df_dist$var1 = factor(df_dist$var1, levels = tax_name)
df_dist$var2 = factor(df_dist$var2, levels = tax_name)
txt_color = ifelse(grepl("CE", tax_name), "#1B9E77", "#D95F02")
heat_dist_fl = df_dist %>%
  ggplot(aes(var2, var1, fill = value)) +
  geom_tile(color = "black") +
  scale_fill_gradient2(low = "blue", high = "red", mid = "white", 
                       na.value = "grey", midpoint = 0, limit = c(-1,1), 
                       space = "Lab", name = NULL) +
  scale_x_discrete(drop = FALSE) +
  scale_y_discrete(drop = FALSE) +
  geom_text(aes(var2, var1, label = value), color = "black", size = 4) +
  labs(x = NULL, y = NULL, title = "Distance (Filtering)") +
  theme_bw() +
  geom_vline(xintercept = 6.5, color = "blue", linetype = "dashed") +
  geom_hline(yintercept = 6.5, color = "blue", linetype = "dashed") +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, size = 12, hjust = 1, 
                                   face = "italic", color = txt_color),
        axis.text.y = element_text(size = 12, face = "italic", 
                                   color = txt_color),
        strip.text.x = element_text(size = 14),
        strip.text.y = element_text(size = 14),
        legend.text = element_text(size = 12),
        plot.title = element_text(hjust = 0.5, size = 15),
        panel.grid.major = element_blank(),
        axis.ticks = element_blank(),
        legend.position = "none") +
  coord_fixed()
heat_dist_flR version 4.4.0 beta (2024-04-15 r86425)
Platform: x86_64-pc-linux-gnu
Running under: Ubuntu 22.04.4 LTS
Matrix products: default
BLAS:   /home/biocbuild/bbs-3.19-bioc/R/lib/libRblas.so 
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.10.0
locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
time zone: America/New_York
tzcode source: system (glibc)
attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     
other attached packages:
 [1] doRNG_1.8.6     rngtools_1.5.2  foreach_1.5.2   DT_0.33        
 [5] phyloseq_1.48.0 lubridate_1.9.3 forcats_1.0.0   stringr_1.5.1  
 [9] dplyr_1.1.4     purrr_1.0.2     readr_2.1.5     tidyr_1.3.1    
[13] tibble_3.2.1    ggplot2_3.5.1   tidyverse_2.0.0 ANCOMBC_2.6.0  
loaded via a namespace (and not attached):
  [1] splines_4.4.0                   cellranger_1.1.0               
  [3] rpart_4.1.23                    DirichletMultinomial_1.46.0    
  [5] lifecycle_1.0.4                 Rdpack_2.6                     
  [7] doParallel_1.0.17               lattice_0.22-6                 
  [9] MASS_7.3-60.2                   crosstalk_1.2.1                
 [11] MultiAssayExperiment_1.30.0     backports_1.4.1                
 [13] magrittr_2.0.3                  Hmisc_5.1-2                    
 [15] sass_0.4.9                      rmarkdown_2.26                 
 [17] jquerylib_0.1.4                 yaml_2.3.8                     
 [19] gld_2.6.6                       DBI_1.2.2                      
 [21] minqa_1.2.6                     ade4_1.7-22                    
 [23] multcomp_1.4-25                 abind_1.4-5                    
 [25] zlibbioc_1.50.0                 expm_0.999-9                   
 [27] GenomicRanges_1.56.0            BiocGenerics_0.50.0            
 [29] yulab.utils_0.1.4               nnet_7.3-19                    
 [31] TH.data_1.1-2                   sandwich_3.1-0                 
 [33] GenomeInfoDbData_1.2.12         IRanges_2.38.0                 
 [35] S4Vectors_0.42.0                ggrepel_0.9.5                  
 [37] irlba_2.3.5.1                   tidytree_0.4.6                 
 [39] vegan_2.6-4                     permute_0.9-7                  
 [41] DelayedMatrixStats_1.26.0       codetools_0.2-20               
 [43] DelayedArray_0.30.0             scuttle_1.14.0                 
 [45] energy_1.7-11                   tidyselect_1.2.1               
 [47] farver_2.1.1                    UCSC.utils_1.0.0               
 [49] lme4_1.1-35.3                   gmp_0.7-4                      
 [51] ScaledMatrix_1.12.0             viridis_0.6.5                  
 [53] matrixStats_1.3.0               stats4_4.4.0                   
 [55] base64enc_0.1-3                 jsonlite_1.8.8                 
 [57] multtest_2.60.0                 BiocNeighbors_1.22.0           
 [59] e1071_1.7-14                    decontam_1.24.0                
 [61] mia_1.12.0                      Formula_1.2-5                  
 [63] survival_3.6-4                  scater_1.32.0                  
 [65] iterators_1.0.14                tools_4.4.0                    
 [67] treeio_1.28.0                   DescTools_0.99.54              
 [69] Rcpp_1.0.12                     glue_1.7.0                     
 [71] gridExtra_2.3                   SparseArray_1.4.0              
 [73] xfun_0.43                       mgcv_1.9-1                     
 [75] MatrixGenerics_1.16.0           GenomeInfoDb_1.40.0            
 [77] TreeSummarizedExperiment_2.12.0 withr_3.0.0                    
 [79] numDeriv_2016.8-1.1             fastmap_1.1.1                  
 [81] rhdf5filters_1.16.0             boot_1.3-30                    
 [83] bluster_1.14.0                  fansi_1.0.6                    
 [85] digest_0.6.35                   rsvd_1.0.5                     
 [87] timechange_0.3.0                R6_2.5.1                       
 [89] colorspace_2.1-0                gtools_3.9.5                   
 [91] utf8_1.2.4                      generics_0.1.3                 
 [93] data.table_1.15.4               DECIPHER_3.0.0                 
 [95] class_7.3-22                    CVXR_1.0-12                    
 [97] httr_1.4.7                      htmlwidgets_1.6.4              
 [99] S4Arrays_1.4.0                  pkgconfig_2.0.3                
[101] gtable_0.3.5                    Exact_3.2                      
[103] Rmpfr_0.9-5                     SingleCellExperiment_1.26.0    
[105] XVector_0.44.0                  htmltools_0.5.8.1              
[107] biomformat_1.32.0               scales_1.3.0                   
[109] Biobase_2.64.0                  lmom_3.0                       
[111] knitr_1.46                      rstudioapi_0.16.0              
[113] tzdb_0.4.0                      reshape2_1.4.4                 
[115] checkmate_2.3.1                 nlme_3.1-164                   
[117] nloptr_2.0.3                    rhdf5_2.48.0                   
[119] proxy_0.4-27                    cachem_1.0.8                   
[121] zoo_1.8-12                      rootSolve_1.8.2.4              
[123] parallel_4.4.0                  vipor_0.4.7                    
[125] foreign_0.8-86                  pillar_1.9.0                   
[127] grid_4.4.0                      vctrs_0.6.5                    
[129] BiocSingular_1.20.0             beachmat_2.20.0                
[131] cluster_2.1.6                   beeswarm_0.4.0                 
[133] htmlTable_2.4.2                 evaluate_0.23                  
[135] mvtnorm_1.2-4                   cli_3.6.2                      
[137] compiler_4.4.0                  rlang_1.1.3                    
[139] crayon_1.5.2                    labeling_0.4.3                 
[141] plyr_1.8.9                      fs_1.6.4                       
[143] ggbeeswarm_0.7.2                stringi_1.8.3                  
[145] viridisLite_0.4.2               BiocParallel_1.38.0            
[147] lmerTest_3.1-3                  munsell_0.5.1                  
[149] Biostrings_2.72.0               gsl_2.1-8                      
[151] lazyeval_0.2.2                  Matrix_1.7-0                   
[153] hms_1.1.3                       sparseMatrixStats_1.16.0       
[155] bit64_4.0.5                     Rhdf5lib_1.26.0                
[157] highr_0.10                      SummarizedExperiment_1.34.0    
[159] rbibutils_2.2.16                igraph_2.0.3                   
[161] memoise_2.0.1                   bslib_0.7.0                    
[163] bit_4.0.5                       readxl_1.4.3                   
[165] ape_5.8                        Lahti, Leo, Jarkko Salojärvi, Anne Salonen, Marten Scheffer, and Willem M De Vos. 2014. “Tipping Elements in the Human Intestinal Ecosystem.” Nature Communications 5 (1): 1–10.
Lahti, Leo, Sudarshan Shetty, T Blake, J Salojarvi, and others. 2017. “Tools for Microbiome Analysis in R.” Version 1: 10013.
Lin, Huang, Merete Eggesbø, and Shyamal Das Peddada. 2022. “Linear and Nonlinear Correlation Estimators Unveil Undescribed Taxa Interactions in Microbiome Data.” Nature Communications 13 (1): 1–16.
McMurdie, Paul J, and Susan Holmes. 2013. “Phyloseq: An R Package for Reproducible Interactive Analysis and Graphics of Microbiome Census Data.” PloS One 8 (4): e61217.